BuddyPress.org

Answers:

1) Yes. It’s on the roadmap for BP 1.2.

2) The WPMU abstraction layer that Andy has coded for single WP compatibility should work in most cases. However, I can’t say for certain.

3) Realistic release for WP 3.0? I’d say mid- to late- 2010. So definitely not in the first half of 2010!

These are just my thoughts. Maybe the BP dev team can chime in for a more, accurate response.