I tried this out today as well. It seems nice enough.. though i didn't get a chance to check it out on many of my own websites, to see how it handles XHTML & CSS yet. It's good that all the major vendors are moving to support those and other web technologies more closely.
Personally, i just want browsers to get better and faster at opening all types of websites, simple to complex, without being a memory hog, so i hope they continue down that path. The only feature i use, that i noticed missing (or did i just not see it?) was a bookmark manager.
I too would prefer the standard OS look, but i think they might just be doing it to differentiate it from the others in the early days. Non-web-savvy users are notoriously bad at even realising WHAT the web browser is!
No doubt it'll be hard trying to describe to some of my clients the difference between Google the search engine and Google Chrome the web browser.. considering most of them think Google is their address bar already!