Anyway, there are several threads discussing the state of the game right now, and I thought I'd comment on my (admittedly limited) personal experience so far, as well as make some of my own observations.
[D]Zerg Threat in Early Game
When I got into the beta, I really had no idea what was standard. I knew roaches and marauders were popular, and voidray/banshee/reaper/hellion rushes were common. So before I played any ranked games, I familiarized myself with the UI, hotkeys, unit costs/HP/damage/etc. in some 1v1 comp stomps, and came up with a basic build:
-don't actually know the numbers, but I had it timed so that my inject larva and roach den would finish just as I had enough min/gas/supply to build 6 roaches
-afterward, second gas/lair/macro/expo.
I would make a few lings for scouting, and I always send my first 2 lings to the watchtowers. I'm surprised this isn't done more often. You see everything coming your way.
I used this build for ZvT and ZvZ, and for ZvP I just kind of got speedlings and went from there, which usually resulted in mass hydra/muta on 2 base.
Of course, now I've read a bit on the SC2 strategy forum, I'm pretty sure that build qualifies as a "roach rush," which brings me to my first thought:
The way the game is played now is nothing like how it will be played in even one year. Currently, many players are just figuring out some "XXX unit rush" build, and going with it. They'll see what it works against, what it doesn't work against, and what timings are involved, and they'll develop better builds as a result. This is already happening. Against gold players, every game I've played has been me fending off some type of rush (voidray, banshee, proxy 2gate...). Against platinum players, it's been 50/50 between some well-executed rush and a macro build.
The biggest possible exception to the italicized statement IMO is Zerg. They really don't have many viable opening options. One reason is limited unit compositions before lair tech. One reason is great walling/defensive abilities of the other races. One big reason IMO is that, while Terran and Protoss have units that they can "rush" and be effective with (one or two unanswered banshees/voidrays/whatevers can be gg), Zerg doesn't have anything like this. Three mutas are an annoyance at best, and T and P will already have the infrastructure to deal with them, or at least minimize the damage. The difference is, to harass as Zerg, you need lots of units, which requires lots of economic strength, especially gas. Players are gas-starved in SC2 more than in BW. While a couple hundred gas can put together a rush for T or P, Zerg needs lots more, which can't be done on one base, nor can it be done in a timely fashion.
However, I'm not saying that's a problem. Zerg doesn't really have a whole lot of rushes in its arsenal in BW either. But part of it is the way the opponent plays. And I think that'll change over time. Namely, once Zerg players are able to consistently stop rush builds from Protoss and Terran, while pursuing a strong economic opening, Protoss and Terran will have no choice but to FE themselves to keep up economically.
So, continuing my story, I went 4-1 in placement matches and got placed in gold. The game I lost was to a voidray rush, that I could have won, but I didn't know that any two buildings next to each-other made a ling-tight wall. That's really too bad. Had I known that, I would have just run past his cannons and destroyed his main, but I got greedy and thought I could win it right there. Also, cannons have 300 life now? Wow. It's needed because roaches do so much damage, but it makes lings pretty worthless against them.
Anyway, after those matches, I watched Artotis' stream. And it was awesome. He played some great games on the Asia server, as Zerg, and answered questions afterward. Very informative. The biggest thing I learned is that FE is still an option for Zerg.
So, FE is viable it seems (I mean, I assume Artosis knows what he's doing, and that's what he does). And as I've said, T and P will need to FE themselves to keep up eventually. But the question is, will they be able to keep up even then? IMO, Queen is much, much stronger macro tool than MULE or Chrono. I think T and P will have to FE while still pressuring the Zerg with aggressive tech timings, harass, or both, otherwise Zerg will just out-power them. Droning up is so easy in SC2, that in fact, watching replays of myself, I usually end games with 80+ drones. It's so easy I've been making too many! But I was a macro-whore in BW too. With the Queen as strong as it is, I think Zerg might become dominant too easily if they had more options available early.
MBS is fine I think. Personally, I still hotkey each hatch separately, since I'm so used to using them like location keys from BW. Automine, I guess it's a necessary evil to keep up with the times, and other than being bored for the first minute of the game, I still find myself with lots to do, due to the new macro mechanics.
Oh Micro, Where Art Thou?
I'm not really sure what to say here. Micro is much easier due to smartcasting, though I don't have much experience with that first-hand. If you don't include army positioning as part of micro, then it's a strong argument, as there's really not a whole lot to do other than put your units in the right spot/formation and attack. After that, you micro the units you have to keep them alive as long as possible, by pulling back lings that have taken 2 zealot hits, forming a concave in ranged vs melee battles, etc. But I think the fact that melee units aren't used as much makes most games just a range vs range battle, and there's not a whole lot to do there it seems.
Unit AI is pretty smart nowadays. Avoiding overkill (I haven't witnessed this myself, but I've heard about it), and quick surrounds both contribute to quicker battles, and more difficulty retreating from bad situations, leading to more one-sided battles if you get caught with the wrong unit combination.
edit: regarding micro, immediately after writing this I saw this thread, and though some of the things mentioned are actually pretty basic, there's a couple interesting things in there. So I guess there are some "tricks" found already. Good news.
Zerg Unit Diversity
Before I got into the beta, watching the occasional stream, it looked like Zerg was all about mass roach, mass hydra, or a combination of the two. So far, for me at least, it kind of is, but I haven't found it to be a problem so far at least. It could get boring quite easily. Overall, I think Zerg could be improved on, and before I heard of the release date I was expecting a major overhaul. That said it's not bad. What would I change? Offhand, I'd consider
1. making the Queen a less powerful macro tool,
2. giving them more viable pre-lair options that get around a blocked ramp and/or harassment options that cost <300 gas to initiate,
3. giving them a cost-effective early/mid-game anti-air option besides hydra
4. making hive tech more attractive
5. giving them another spell-caster besides infestor
6. changing at least one of the infestor's spells
I'll stop there.
I'd prefer a much more unified ranking system. One that allows players to make inter-division and inter-league comparisons. Why are there hundreds of "Platinum League #1's?" Who's actually #1? How does a 2000 gold player measure up against a 1250 platinum player?
Is it fun? Yes (at least for now). The matchmaking is great too, so that players can have fun against similarly skilled opponents.
Is the skill ceiling high enough? Yes, I think so.
Great spectator sport? ... It's fun to watch replays, that's for sure, since they're like FPVoDs and so comprehensive. I'm confident there will be PLAGUU!! and Rebo-Rebo-Rebo moments, as players refine builds to the point where one important unit sniped or well-cast spell is a big deal. I guess, yeah, it'll be a good spectator sport, as long as players and mapmakers are willing to innovate, and Blizzard is willing to make balance changes every once in a while.
Really, only time will tell, but those are my thoughts as of now. I'll probably read this a year from now and laugh at how wrong I was.