According to Neowin a new Community Technology Preview of Windows Vista will be released today:
With a build tag expected to be 5308.x86fre.winmain_idx01.060217-2200 the CTP is likely to be near feature complete.
Microsoft yesterday invited press to a conference call at 6:30pm GMT today to talk about the Windows Vista development process. It's expected that shortly after the conference Microsoft will announce the availability of the February CTP.
The next CTP is expected in April.