So it's here and I've been using it for about an hour now. First impressions are very good, it has a very simple, minimalist UI and I like it!
I don't have anything solid to back up my claims, but sites certainly appear to load faster in Chrome than they do in Firefox. In fact a quick test with www.bbc.co.uk reveals that Firefox loaded the page in 8.84 seconds while Chrome did it in 7.3 seconds. Nothing scientific in that, but it gives you an indication.
It also uses less memory, with Firefox and Chrome both having one tab open with identical pages fully loaded reveals Firefox using 125,684k and Chrome only 29,636k. Now a lot of that could probably be accounted for by the various Firefox plug-ins I've got. But that's still pretty impressive stuff!
One thing I am impressed with is the drag and drop. I can take a tab and pull it off the browser to make it a new window. What was particularly cool was discovering that you can drag tabs from Firefox straight into Chrome!
I've not experienced any rendering issues so far either, all the site I've tried work really well. The incognito mode is an interesting idea, you can open a new window in this mode and all your browsing will be kept secret, no bookmarks or cookies will be left behind. They say this is to let you shop for surprise presents, but I think we all know what they really intend it for :-)
Not so sure I get the new Omnibar which combines features of the address bar, and Google toolbar in one. I really loved the Firefox 3 address bar, but so far I'm just not getting the same great experience with it. That might change in time though.
In summary, this is going to be a strong competitor to the big three (IE, Firefox, Safari). Not sure I'm ready to give up Firefox with all its plug-ins just yet but I could see a time when that may happen!