The Pitt is out. The Pitt is also incredibly buggy. A modder has put out a file that fixes a large portion of the crashes.
http://www.fallout3nexus.com/downloads/file.php?id=5152When asked about this and the status of upcoming patches a Bethesda representative simply put his fingers in his ears and stated "La la la la la la la la la i can't hear you la la la la la la".
Regardless of crashing, its worth playing. Probably not worth paying for. Like you were even considering that though.