BuddyPress.org

You could try upgrading your site to MU but, personally, I would simply wait for the WP version of BuddyPress to arrive.

My guesstimate is that Andy will aim to coincide with the release of WP 2.8, currently scheduled for the beginning of April put will probably get pushed back to the middle of the month. He has said that the non-MU version of BP is almost ready to roll but I guess he wants to see how the release of the MU version goes first and, obviously, he isn’t going to release for 2.7 with 2.8 so close.