My response is the same thing I'm told when I complain about a product or service: if you don't like it, don't buy/utilize it.
If game producers don't like the used game market, then stop making games. Although I doubt they well, because despite all their complaints about piracy, used games, and whatever else, they still make games. Clearly games are profitable or there wouldn't be this entire industry, so as far as I'm concerned they can quit their bellyaching.
Of course, I'm not saying they couldn't instead try and fight the game market. If they think that will bring them more money then that's their choice. But if I can't resell a game, I will spend considerably less (or skip it altogether) on it. As an example, I generally don't buy games on Steam, and will only make an exception if it's a game I"m really interested in (Shogun 2, Portal 2) at a low price (I'd say $10 max, preferably $5). I'm probably in the minority though.
As an aside, I don't think I've actually sold one of my games. Probably because I generally buy games at lower prices ($20) after they've been out a while, and so reselling them won't recoup a significant amount of my costs. As someone early mentioned, lowering prices would probably help combat used games without directly attacking them.
I've also found that I don't often buy used games, once again because by the time I get around to buying a game the new game is only a few dollars more (sometimes they're actually cheaper) than a used copy. The only exceptions I can remember are PS3 games released as Greatest Hits; I bought LittleBigPlanet, Ratchet & Clank, and Heavy Rain used because I didn't want one of the red bordered cases (aesthetic reasons). Oh, and I also bought some old ps1/ps2 games used.
Unfortunately, I do see a move to cloud based gaming in the future. By tying games to accounts publishers can practically eliminate game resales and piracy. Fortunately, when that day comes I'm sure there will be enough old games I haven't played (e.g. the entire Nintendo catalog) that I wouldn't have to buy a new game for the rest of my life.