The odds are already stacked against the attacking force. In fact, they're stacked in favor of the defense more so than we would like at this point. We're looking to address this in an upcoming patch so that defending Tol Barad doesn't feel like there's virtually no fear of loss.
In line with that design goal, we made this hotfix to ensure winning Tol Barad back for your faction feels much more rewarding.http://us.battle.net/wow/en/blog/1232869
December 22 - 27 Cataclysm Hotfixes
Winning as an attacker now rewards players with 1800 Honor Points, up from 180. Winning as a defender still rewards players with 180 Honor Points.