Right now, it's a bit hard to get some more info since their servers are getting hammered with requests this morning. From what I understand so far, it uses the WebKit engine and it features a devious twist when approaching the speed optimization competition that was going on between Firefox, Safari and to an extent, Opera: it will have a per-tab performance monitor so that if the browser starts to slow down, users can blame sites, instead of browsers.
From Google's perspective, that move is truly a stroke of genius. It will force web developers to become more responsible with their code, rather than relying on the browser's Moore's Law. At the same time, it lessens the expectations from browser critics towards Chrome itself.
Now the question is: when can I download it? :)
Update: to answer my own question - Here.