Who's excited? I'm excited.
I love the idea of the Metro UI to remove distractions and make computers more efficient (suspended apps will be taken off the CPU scheduler and most likely the video resources will only be in virtual mem). It was a little awkward on the Dev Preview but that isn't what the CP will look like anyway.
Storage spaces is probably my favorite feature they've talked about so far. I'm not sure I want to ditch my Win7 install yet though, but it probably won't take long using 8CP before I do.
I do wish ReFS was in the client builds, but it doesn't sound like it will be. (At least in the final OS...don't know about the CP.)
I definately like the plugin free browser idea too. Most of the time you browse they're unnecessary anyway.
Otherwise it's mostly just more efficient, and I can't argue with that!