Have not visited W2knews in a while, so while browsing, I found this....
SP3 is in beta testing right now and it is expected that at least one more "build" or update to the SP3 beta will be released. (there has only been a single version released to the technical beta testers so far, and that was in December). It looks clear that there will be another version sometime soon, and that MS is planning at least one more chat session with SP3 testers.
Since the initial SP3 beta release several security patches have been released, and a roll-up security fix for W2K was recently released to the beta Windows Update site before being pulled abruptly because of problems reported with it. I would expect that "roll-up" fix to go into SP3 and in fact maybe thats the delay right now. SP3 could be soon but it may take a month or so.
News source: W2knews