The eager newshounds at NeoGAF have dug up a patent filing from Nintendo revealing plans to emulate Game Boy titles on PC, mobiles, PDAs and in-flight entertainment systems. While this is in no way confirmation that Nintendo are working on bringing out Game Boy titles (original GB, GB Color, and GBA) to non-Nintendo platforms, it at least shows that they might move in this direction. However, the likely scenario is that Nintendo have filed the patent for improve their legal foothold when dealing with the many GBA emulators that flood the Android app market.
Nevertheless we'd love to see GBA titles on mobile. Or on in-flight entertainment systems. Or, well, just about anywhere really.