A recent post on Mozilla’s developer mailing list suggests that Firefox 4 is nearly ready for release, and that the company plans to release the browser some time in February.
"Team, We’ve worked tremendously hard on Firefox 4, and it’s time to ship it... We must press hard now."
I've tried the beta and it really seems like FF is piggybacking on Chrome's features. Probably won't make me switch back, I love Chrome too much <3