I don't think it will have that much impact on new IPs.
The average gamer is already mostly just buying new games in the franchises they play every year like CoD, Madden etc. already.
For new IPs, they tend to not sell well until they launch with good reviews and pick up good word of mouth. Used games going away doesn't really affect that. People would just be waiting for price drops/sales rather than buying them for $60 at launch like the do the latest CoD or Halo. And that's better for developers than people buying it discounted used.
The other factor to consider is that we're moving toward more games being download only. That will be a cheaper way for developers, especially smaller ones, to introduce new IPs. If they sell well and build a following off a shorter $10-15 XBLA/PSN game then they can make the sequel a big budget retail release.
Again, the only thing I'd dislike if used games go away is not being able to sell/trade my discs since I don't replay games. I have no issues buying things at launch and just waiting for drops/sales on the stuff I don't want to pay $60 for. But honestly, with my declining interest in games, if it's not worth $60 to me it's probably not something I'm interested in enough to buy in the first place. The main way I take advantage of sales is just saving money on games I didn't have time to play around launch by buying them later.
I'm more perturbed by the rumor the new Xbox will require Kinect. I have no interest in using that crap, and it doesn't work well in my condo as I don't quite have the space for it (got a Kinect system free from MS for my hacking debacle a year or so ago--ditched it pretty quickly). So it's just more useless crap to clutter up my home theater that I won't use--and I worry that they'll shoe horn motion controls or voice commands into games if every system is required to have it hooked up to work.
But as the post above notes, all this stuff is rumor. So only time will tell. I'm mixed on whether I'll buy another console after this current generation even if nothing changes with DRM, used games etc., so no real sense in my worrying about it anyway. I'll see what comes out and weight whether I'm gaming enough to buy another console after the first price drop on the new systems.