http://www.teamliquid.net/blogs/viewblog.php?topic_id=342143
i concede that what failsafe had to say about user interface is probably right. a more advanced user interface makes a big difference from a player's perspective.
infinite unit select, infinite structure select, and automining free up so much of the player's attention and allow the player to invest a LOT more time controlling units on the map. players are able to scout much more effectively because they have time to control each scouting unit. players are also able to control units in fights more effectively, because players don't need to move the screen's focus to look at production structures or economic structures to issue more workers to resources.
from a casual player's perspective, infinite unit select, infinite structure select, auto-casting, and auto-mining are all essential. from a competitive player's perspective this is probably not directly true. but what about indirectly? players make money from spectators, sponsors, and general interest in the game and competitors.
you wanted game development feedback, so i'll bite. it doesn't seem that Starcraft 2 improved anything in the Starcraft: Brood War unit line-up. Starcraft 2's game play is a lot less control intensive -- 'micro' in Starcraft 2 is less than in Starcraft: Brood War. Starcraft 2's map presence is greatly reduced, and the scale of army movements and games pales in comparison to Starcraft: Brood War -- Blizzard seems to have greatly underestimated the effect of constant instead of diminishing returns to scale in that players are less incentivized to expand, and the presence of Two Vespene Geysers per base instead of One further enhances reduced map presence. Starcraft 2 is unplayable on maps suited to its reduced unit count and more compact armies, this is owing to game-breaking macro mechanics like Larva Inject and Chrono Boost (while Warp Gate remains a pernicious thorn in Starcraft's side regardless of map size). Starcraft 2 features a variety of 'broken' or imbalanced units like the Banshee (a flying ranged Dark Templar that 2-shots economy units), the Infestor with Fungal Growth and Infested Terran, both of which are at present extreme flaws in game design; the impact of these units on game play cannot be understated (the Void Ray is another extremely problematic unit that like the Banshee is condemned to be either game-breaking or useless). The Thor and the Colossus are both extremely uninteresting 'big' units that do nothing but detract from the game, and the revised Ultralisk isn't that much better.
It seems that Starcraft 2 improved on the graphics of Starcraft: Brood War, at least in some cases. I'm not that impressed with the art. While graphics technology has improved a lot in 15 years, graphics technology is not everything. The game art is just as important if not much more important than the graphics technology being employed. Zerg looks atrocious, and the operation of every Zerg unit as an A-Move kamikaze reflects developers' disdain for 'sleepers'. 'sleeping people' being what Zerg appears to represent in the majority of the developers' minds. just because the word 'Zerg' starts with a 'Z' does not imply that the entire Zerg race should look and play like a caricature of someone who is asleep on the job. we all pretty much get the point that people asleep on the job are not very interesting, so why create an entire race based on reflecting them? anyway i think it's pretty clear that Zerg are supposed to be a lot more sophisticated in operation, an alien hive-mind race, and that 'sleeping humans' should be a minute fraction of the Zerg story.
Terran's appearance suffers from the same developmental prejudices. Terran's art and perhaps also its game play reflect a misguided societal disdain concerning '2'. The entire Terran race is blocky, clunky, and unappealing in it appearance (though not absolutely appalling in appearance like Zerg). Terran units, particularly the Thor and the Hellion handle in a frustrating, clunky way. Especially the Hellion, which just feels awkward to handle with unintuitive attack timings and acceleration. it seems that perhaps the entire development and conceptual team working on Starcraft 2 were united in their efforts to encapsulate their own lingual prejudices in the form of a video game. unfortunately they succeeded. at least Protoss looks cool (although the Colossus and Zealot are both not so good).
perhaps the silver lining is that these same lingual prejudices are pervasive in our society. so, to those who appreciate the language and thought that created Starcraft 2, there is something to be learned from its failure. the development team (especially NonY) did a great job encapsulating the structure of language that could be termed the Western manifestation of language and culture imported from South Korea. so, in some sense, Starcraft 2 does society a great service because it demonstates the problems inherited from an incomplete tongue of Buddhism that has been furthered degraded in its importation to Western society. from that perspective, Starcraft 2 has done some great societal good in highlighting the deficiencies present in a culture and style of language that is adhered to by more than a billion, perhaps billions of people across the world.
however, while the accuracy of Starcraft 2's portrayal of a language and a culture is quite astute, it features all the trademark errors of the culture it so assiduously represents. (think Hellion harass, Banshee, 4 Gate, Void Ray, Mass Speed Reaper, and 111). just how many players Starcraft 2 has lost on account of these units is staggering (we're talking hundreds of millions). so in that sense Starcraft 2 has done society a great service -- emergent game play highlights weaknesses in the language and culture, perhaps better than any theory crafting ever could.
also of great significance, from my own perspective is how successful Starcraft 2 has been in spite of great, great deficiencies in the Battle.net 2.0 Interface, the graphics and artwork, and especially the game play. seeing the success of Starcraft 2 is astounding. the graphics and especially game engine were not up to par given the date of the game release. much of the artwork was quite terrible. the game play is in every way a step back from 1997's Starcraft, and yet in spite of these difficulties Starcraft 2 has been a fairly successful competitive game.
imagine, if instead, Battle.net 2.0 were a great improvement over Battle.net. Imagine if the graphics and game engine were better, and the artwork were much, much better. Imagine if, instead of taking four steps back from Starcraft: Brood War, the game play took maybe two steps forward. The true improvements in Starcraft 2 are that the graphics are a modern 3D and the interface includes major improvements that enable players to perform much more dynamic strategies (player's having much more attention and actions committed to units in the field is what gives the illusion that Starcraft 2 is in some way more dynamic than Starcraft: Brood War; in fact this is not the case, as could be illustrated if basic user interface improvements were applied to Starcraft: Brood War).
So it could be said that small changes make very big differences. The User Interface improvements are so basic in terms of the workload required that probably a skilled team of programmers could make all these same alterations to the Starcraft: Brood War user interface in just one week. And yet I think that truth be told the real appeal of Starcraft 2, if it is indeed in some ways more appealing than Starcraft: Brood War, are owed entirely to the game being rendered in a modern 3D and the user's interface making the game immensely more playable to the casual gamer and permitting more aggressive and attentive army control in spectated matches.