Development is well underway on an 8-bit Nintendo emulator for Windows Phone 7, although it is unlikely that the application will ever get approved for Marketplace inclusion. Developer Matt Bettcher has reportedly succeeded in a rough port of open-source app SharpNES, and has moved on to recompiling My NES for XNA, which will supposedly give faster performance and offer wider game compatibility. A video of the Sharp-based program is embedded below.
Unfortunately for NES owners, Microsoft explicitly forbids any Marketplace applications which it thinks are used primarily to enable IP theft, namely console emulators. Of course, many people still own their old game cartridges, and have ripped the ROMs long ago in order to save the games from their decomposing plastic housings. However, it’s equally true that there is a very healthy game pirating scene online, where it takes all of ten seconds to download a title for one of these older systems.
Ultimately this project will probably remain restricted to jailbroken handsets, which is too bad for those who legally own these games, but understandable considering how easy it is to acquire illegal ROMs — and because Microsoft has a vested interest in protecting its Xbox titles as well.