I'm worried about IE7. I'm ecstatic that Microsoft is developing IE again, but I've played with the betas and it feels half done. I know it's still beta, but I've seen the posts on IEBlog about what they're actually implemented from CSS2.1 and CSS3 selectors, and it doesn't come close to what's already in Safari, Firefox and Opera today. With the way they're removing CSS hacks from IE7, they're not implementing enough of CSS2.1 and 3 to achieve parity with their competitors and are creating a new milestone in the middle that's going to require a whole new set of hacks to be developed without giving developers the standards they're clamoring for.