As of last week when I registered FV.BZ, all two letter .BZ combinations have been registered. I'd hold on to this one for about a year. It's an excellent two-letter combo. If you were to sell the domain right now you would get between $50-$250. If you were to hold on to it, I'd imagine you'd be able to see an offer around $4xx.
Good luck! Let us know how you do and what you decide to do.
I'm gonna go over and register on Counter-Strike.net or whatever it is and see what the highest bid somebody will put for it, just out of curiousity :P