Interesting. As far as getting the rights to the games, I'm sure Microsoft has a lot more pull than StarRoms could have had. Companies like Namco are going to be a lot more receptive to things like this when you combine the Xbox name with the relative ease of ordering things on Xbox Live, not to mention the locked-to-a-Xbox-Live-gamertag security... seems like a no-brainer.
As far as calling it MAME, well, I'm sure they're not actually going to be using MAME.