Some interesting comments by Epic Games boss, Mike Capps, caused a bit of a stir recently (he seems to do this often when he speaks his mind).
Epic has sorta turned their backs on the PC due to rampant piracy, and now they be hatin' the reselling of titles in the console games market, particularly from stores like EB Games who make a killing out of it. It seems a fair reason to get disgruntled over since developers and publishers get zero income from every transaction - each time it changes hands, it denies them a unit of the title sold.
But the idea to charge gamers for a portion (or last level) of a game as downloadable content isn't the right solution, even though Mike Capps doesn't necessarily say that Epic is going down that path. What they are doing is offering downloadable content codes that are for use once only in Gears of War 2, something that Shacknews mentioned was done by EA Canada and Harmonix in NBA Live 09 and Rock Band 2 also.
To me, the secondary market would be a hard one to crack when games are easily finished within 8-12 hours, and with a game particularly like Gears of War 2, is there much replay value after the single player mode? Others have mentioned providing much better incentives for gamers to keep their games, or downloadable distribution (which isn't viable everywhere yet) to tie a gamers computer to the game as solutions to stop them getting resold, but it looks like a problem that's not going to go away too soon.