Just so we're clear here, the 360 isn't getting special treatment. (Well, it is, but not in a good way.) Telltale's games are meant to be downloaded. As episodic games, they're small (and...meant to be released episodically). Even if you put all the episodes of any one of their games together, I think it'd be too small to really deserve a retail release.
Thing is, XBLA is a pretty restrictive service, and Telltale's past experiences with it have been so awful that it seems unlikely they'll ever release anything on it again. Telltale doesn't want to ignore the 360, but they also don't want to put Jurassic Park on XBLA, so a retail release it is. PS3 owners shouldn't feel like they're getting screwed. They're pretty much being told that the PS3 has the best downloadable game service (well, as far as consoles go

).
And on a semi-related note, Steam has taught me that downloadable games as a whole are better than physical releases. You can't lose your copy of the game, your game collection can't take up a lot of space in your house, and since they're not mass-producing hundreds of thousands of plastic discs it's better for the environment too. Sure, the install times can be a pain, but that seems like a small price to pay for everything else. I've made it a point to (legally) download games instead of buying retail whenever that's an option (not that there are too many games that interest me these days). Hopefully gaming as a whole will be downloadable in the near future.
But anyway, getting back on track...even though nothing's been confirmed, BttF did get a retail release for the PS3 after its PSN release, so I wouldn't be surprised if the same thing happened with JP.