BuddyPress.org

I don’t know of any straightforward migration tools, unfortunately. I don’t know much about Drupal’s export capabilities – maybe something like this http://groups.drupal.org/content-migration-import-and-export would get the data into a usable format. Then you could write a couple of basic WP/BP loops to do the importing. Do you know anything about PHP programming?

The standard WP import XML format is really meant to handle WP content (posts, pages, tags, etc) rather than users and BP data. If you want to see an example of some PHP that processes data for import into BP, you may be interested in https://github.com/boonebgorges/Import-from-Ning/blob/master/bp-functions.php