Re: BP Development Pre-Merge: WP or WPMU
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.