There have been a few performance issues in the past couple of weeks and it has been discovered that groups are a big part of the problem. It was an unsupported, poorly written third-party add-on from the previous version of the site. With the new chat going online, and the system resources it will consume being a concern, chat looked less and less like something that could be fixed. No one has been sitting on this info and giving short notice on purpose. I do know Simon was actively seeing if the groups issues could be resolved, up to a few days ago.