If you look around the Facebook for BlackBerry application permissions you’ll find that the application asks for permission to Login to Facebook Chat. We have seen the leaked features for upcoming versions of Facebook for BlackBerry and there was no mention of Facebook Chat, meaning this sort of feature is more likely to come with Facebook 2.0.
Ideally, RIM would begin to consolidate these chat services under one large IM application. Perhaps it would make sense to make them all integrated into BlackBerry Messenger allowing you to log in to any chat service you want and manage your contacts accordingly. The current system of having them all as separate apps is tedious and lacks creativity.