Mike R makes a good point here when he says that "data leak prevention (DLP) stalls in 2008, continuing to be a solution looking for a problem. " He also predicts that DLP will suffer in the marketplace from "poor man's DLP" or "good enough DLP using other technologies."
I plan to outline just such a plan: poor man's DLP using logs. Yes, it will suck :-), but it will be free, not "$500,000". What can I say, 'Welcome to the world of "good enough technology!"'