BuddyPress.org

You could wait the integration of bp in wp,

or (i think it’s better) you could try copying some tables in your new mu install:

example:

copy wp_users to wp_users

wp_postmeta to wp_1_postmeta

wp_posts to wp_1_posts

etc etc..

that’s a bit difficult to do, maybe others could help you better than me..

Nicola