My only complaint so far is that I miss the bar at the bottom of the browser that typically displays the active link and download status. I find the little pop-up distracting.
If this survives the day without a stability issue it becomes my primary browser.
And text boxes are expandable! (Or is this a News.YC feature I missed?)
Edit: Last paragraph wrong on both counts; see response.
It's certainly fast, though, and probably will supplant FireFox as my gmail browser. The tab switching animation is slick too. Definitely looking forward to how this develops. Seems more like a web application browser and less like a web page browser, which is obviously something Google needs to seriously attack Microsoft's desktop monopolies.