Retailers don't make much money off new game sales. Even bought at wholesale and in quantity a retailer is lucky to make $5 (net) off a new game if even that. Ever wonder how Wal-Mart sells everything at a lower price than anywhere else except video games? There's no room in mark-up to cut prices without cutting profits so they're the same price as EB or Target or Blockbuster.
If publishers want a cut, then they should start their own chain of stores to sell their own used games. If they expect a cut from the EB/Gamestops or mom and pop game stores they're sadly mistaken. They can't give up a cut of the only part of the business that keeps them afloat. Publishers and developers are going to witness the death of brick and mortar stores to sell their wares and bow to submission to the Wal-Marts, K-Marts, Targets, Best Buys and the like. When the big-box boys won't hold "ultra-violent video games" on their shelves due to parental or governmental pressure, there goes the M rating just like Ao went the way of the dodo and the publishers/developers can do nothing about it.
Publishers and developers need to rethink the way their games are developed if they're struggling so badly for cash. There's too many AAA budget games and too few AAA quality games. There's no point spending a hundred million bucks on polishing a turd, yet they seem to do it every day and I, the consumer, am expected to pick up the pieces? Umm, no.