The fact that they focused on the Protoss innovations was intentional...apparently they want to reveal the new Terran and Zerg innovations closer to the release date. I wouldn't judge the game as a whole at this point, probably later on when they reveal more of the new stuff. The first-impressions are pretty good. The graphics are sharp and colorful...apparently some people don't like it, but then again photorealism is overrated. I'd rather have the graphics look like what they do now at release, and have a game that runs well on a decent computer and is balanced and fun to play.
As to overhype, a lot of other companies would probably drop the ball...not saying that Blizzard won't, but they'll take their time to get it right. After all, they have a lot more riding on Starcraft 2, reputation-wise, than EA has riding on...say, C&C3 or Nintendo on the next Zelda game (they only have 3 franchises!). Still, there will always be people who will be disappointed when it comes out.