JB
These days I definitely prefer new, but I definitely remember when I was a kid and new NES games were still $60 back in the 80's economy! The only way we were able to play a decenct variety of 8-bit cartridges was to trade with friends, or walk down to the grocery store for a $1.99 weekend rental 
The times they are a-changin' though. Without any real specifics, it seems to me the big winners in this scenario are developers, especially the mid-range ones, and the losers are rental services like Gamefly, and that chain-what-won't-be-named that specializes in used games. So the question is, which benefits the gamers more - supporting the secondary market, or supporting the people who make the games we love...
I can agree with supporting the company that makes the games. This is cool. I've even imported some great games that are region-free not only to support the dev, but to support the whole 'region-free' thing.
What I don't like is being told what I can and can't do with my game after I bought it. I'm not allowed to lend/trade/sell the game I bought to a friend of mine, because he didn't support the developers? It's restrictions like this that create piracy. If, for example, I want to buy a game that's been long out of print, there's no used game market to turn to. I'd have to either find someone still selling a brand new copy (likely on an online auction site, likely for double the price it released for due to demand, which still doesn't support the devs anyway) ...or I can download that game, then mod my console to play it. And then there's just plain pirating out of spite -- who remembers the release for Spore for the PC? It became the most pirated game ever, mainly due to its restrictive DRM.
This is the only media where this is a real problem, too. Nobody cares if a friend of mine borrows a DVD I bought, even though he isn't 'supporting the studio.' I listen to music on the radio all the time, even though I've never bought any of that music. Why are videogames any different?
Although I agree with you, the radio analogy doesn't work - artists still get paid royalties based on radio play, the only difference is it doesn't matter if you personally are listening or not...
The DVD comparison is bang on though. I lean toward supporting the devs as opposed to the secondary market, but I absolutely can't fathom not being able to loan a movie to a friend, so why should a game be any different. In my opinion this really only works if the games are completely digital. Maybe the Steam model is the future. Once you stop selling a physical product, and begin selling licenses to use instead, the concept (whether appealing or not) becomes more realistic.
I'm less inclined to comment on how piracy affects the situation. Piracy sucks, but I think it's a whole conversation on its own, regardless of the situation. In my opinion a specific move like this from say, Microsoft's perspective, is sparked more from contempt for the secondary market, battling a legitimately legal aspect of the market that it feels has its hand in the corporation's pockets.
Digital rights of ownership is a whole other can of worms too. I can't imagine how the less technologically inclined would react to the complete digital licensing of the movies, games etc. It is hilarious to browse forums grounded in the eBook industry, and see all the angry people who are completely puzzled as to why they aren't able to sell their "used" eBooks back to the retailers or friends once they are finished reading them 
