Just a heads up for anyone interested, m.k. the guy who ported SNES8X just released VBA8, a GBA Emulator for Windows RT and 8. Xbox controller works as well.
Check it out, SNES8x is available on the Windows Store now! And it's free!
Here's a link to the news with a video! SNES Emulator Released for Windows RT
Also here is the Windows Store Link
Check it out: