Chrome was very fast at executing JavaScript, which is important these days because it's so frequently used, but otherwise had a poor feature set when it was launched. It is steadily improving though and maybe this time next year it will be an OK web browser. It certainly needs more features and not just extra speed.
The latest beta version was released on 5th August and it is claimed to be 30% faster than the current stable release. Fortunately, the improvements aren't all about the speed and some new features have been added and old ones tweaked too. It's not worth listing them all here, but to find out what's new in the latest beta of Chrome you should read the Google Chrome Blog.
So development of the Windows version of Chrome is racing ahead, but the linux and Apple Mac versions haven't even been released yet. It seems like development is taking place at a snail's pace. Why? Is it really so difficult to write software for the Mac and linux?
For those that are interested though, you can get betas of the linux and Apple Mac OS X versions here. (Most Google stuff is beta, but these are even more unfinished/unstable than usual.)