Hot off the press is the announcement of the BuddyPress template packs plugin. This plugin makes it very easy to use your current theme with BuddyPress on a single site install of WordPress instead of having to use the default BuddyPress theme. Kudos to Andy Peatling for making it even easier for people to use BuddyPress without reconfiguring their entire site. Note that the template pack won’t do anything unless you have BuddyPress installed.
Using BuddyPress With Existing WordPress Theme