I'm trialling Chrome right now, with firefox very much still around.
Plus for Chrome:
rewritten javascript engine - very fast!
sandbox tabs - good to have the separation
developer/inspector - rather like firebug
slim, streamlined, seems efficient
No need to download/install flash players etc before use, it just works
Minus for Chrome:
no adblock or similar (though I'm sure one will appear soon)
I like add-ons!
the task manager is a nice idea, and it's good that they copied the ff3 method of zooming the whole page, not just the text. Loads of (often badly designed) websites do not text zoom well. Also you can have pop-down folders in the bookmarks toolbar.