One small fix I did right off the bat:
I moved the css/ and js/ directories into the included bbpress/ one and changed several references to their location in the bbp-twentyten templates. This allows the top-level theme directory be just a bit cleaner, as I know my theme (and many others) already have a css/ or js/ directory. Moving those into the bbpress/ sub-dir improves “clutter” and compartmentalization, IMNSHO.
Does anyone see any problems with this approach that I’m not seeing?