Nintendo filed a very interesting looking patent recently. It is what appears to be a case for a mobile phone. The idea of the case seems that it will turn the device that is inside it into a Game Boy!
Nintendo has had amazing success (no thanks to their distribution) with their classic mini consoles so having a case for a phone where people can download Game Boy games to their phone and then use the case which would have Bluetooth buttons seems a good idea. Of course, with there being so many different models of phones you would have to think that something like this may be just aimed at Apple products as that would be easier than making a case for every single size and style of Android phone.
There is of course also talk about Nintendo making a Game Boy Classic to go along with their NES, SNES and inevitable N64 Classic Mini Consoles. I think that a Game Boy Classic would be huge. There have been mini systems that play Mega Drive, Master System and Neo Geo games before, but the Game Boy is something truly special and something many people would want to snap up.
The original Game Boy has a horrible screen so that would be one of the main things that would be fixed. Plus it would be interesting to see if they included Game Boy Color games on it or if they would make separate Game Boy Color and Game Boy Advance Classic Consoles. I have to be honest and say that as a collector I would rather three different Mini Game Boys with each one being dedicated to a particular version.