I have branched off 4.6 this AM (for some reason I couldn't connect to openacs.org when I tried last evening, so it didn't get tagged yesterday as promised above).
The tag is oacs-4-6. After testing we'll move to oacs-4-6-beta-1 etc. If you fix bugs in 4.6 please remember to first check out a copy from the oacs-4-6 branch. This works for me:
cvs -ddonb@openacs.org:/cvsroot checkout -r oacs-4-6 -d openacs-4-6 openacs-4
Bug fixes will be merged into the HEAD after 4.6 is released.