So, apparently the BUS is an implementation of the CAL rules PUG that many of you have played, in which the marine team in Combat are the attackers and aliens are the defenders with a time limit. At least, this is what it appears to be, from what I played tonight. Is this the BUS or is this just a minor change?
EDIT: Hmm, read the changelog, guess this isn't the BUS, but rather an old feature being put back in. Dang! I lose!