At least for now I'm 100% Chrome from Firefox just a couple months ago. There are some things I still like better in Firefox (like the ability to synchronize passwords using Xmarks and the ability to completely block ads instead of just hiding them), but the load time got to be PAINFUL. For me, with a comparable bunch of plug-ins it's maybe a 5 second cold start for Chrome and a 30 second cold start for Firefox. Ridiculous.
I eagerly await FF 4.0. I do much prefer working with an open-source browser vs. a Goliath-owned one.