What I've found is that static defense still does a lot of damage for not a lot of cost. Spines for example still do 20 per hit for 100 minerals. So static defense still helps when defending. This cannot be denied. What intrigues me is people saying that it is MORE efficient to attack then it is to defend. I do not believe this is true at all. Building a sunken in your base is equivalent to about having a unit in the back that has an attack damage of 20. You still have a formidable advantage if you build static defense because of the damage that static defense can do from behind. The main thing is that you have to supply units to defend it. Sure static defense can't take as many hits as before, but again I think that static defense being weakened was apart of blizzard's plan to discourage turtling.
That being said, defending in general needs to be strengthened. A uphill mischance would be great for one, but I don't really know how this problem can be remedied.
As for zvz, I have a couple of comments. I'm a zerg player and I don't feel that roach is the only way to go. I've lost and won plenty of games using ling-bling combos. (I like the name ling-bling). Also I've seen strategies which have employed banelings and spine crawlers with a follow-up tech into muta. If you think about it, SCBW only really employed mutas and lings the entire time. Roach, zergling, baneling, muta.... that's already double what it was before. Second I do agree the scouting is tough but not impossible. Sending a zergling or two from your base hardly hurts your chances of winning a fight and it gives you good enough scouting of the base. Two lings getting killed is often far more than enough to realize how big of an army he's got at his front door, and you can plan accordingly. Also, there's a queen there with an air attack, great. This doesn't mean you have to suicide your overlord to get vision over his base. Hovering it near the base or off a ledge where the queen can't reach is good enough. Even the so called "times where it impossible to scout the main can be solved by simply placing an overlord in an opportune place.
Just my opinions from playing the game.