If you want to follow CSSU development over a thread (where you can report problems with the current CSSU) go here:

http://talk.maemo.org/showthread.php?t=67905

If you want more details about latest versions (what was fixed or what changed) you can visit the changelog:

http://wiki.maemo.org/Community_SSU/Changelog

But when the CSSU developers are about to release a new update, you'll generaly find out at the first link I gave you.