If this works for all cataclysm raids or just BH I haven't been able to figure out just yet, however this is useful for getting gear on one of your alts. I'm not sure if its based on a % of mobs killed in the raid or what but anyhow.
Basically we were in BH and we killed the three trash mobs, I swapped over to my healer for the actual boss fight (Pit), we downed him. Nothing for my priest dropped so I logged off back on to my hunter and our DK tank showed me the stats on his gear he won (due to me not paying attention since it wasn't for my toons) and it allowed him to trade it to my original toon who didn't kill the boss only the trash.
TLR
Kill trash mobs in BH on one toon.
Switch toons for the actual boss fight.
Down him, possible to trade gear to original toon who only killed trash.
Reward:
Chance at getting gear for two seperate toons.