It seems the core developer doing lots work any they are a bit behind the schedule. The Developer team informed that they are adding a new menu system that why they are delaying the release date about 2 weeks. They announced project freeze date on March, so we should see a Public beta within 2 weeks from it. We all waiting a lot for this 3.0.
We got this image from closed built svn reported by WordPressPlanet.com
They also published a schedule, take a quick look.
March 1, 2010 – Feature freeze
March 15, 2010 – Begin public beta
April 12, 2010 – Begin RC
May 1, 2010 – Launch WordPress 3.0
Resource: WordPressPlanet.com