WiiMednafen is a port of the Mednafen [1] emulator.

Emulators supported:

GameBoy/GameBoy Color
GameBoy Advance
Game Gear
Lynx
Mega Drive/Genesis
Nintendo Entertainment System (NES)
Neo Geo Pocket
PC Engine (CD)/TurboGrafx 16 (CD)/SuperGrafx (Fast version)
PC-FX
Sega Master System
Virtual Boy
WonderSwan
It should be noted that the Virtual Boy emulation included with this emulator is much improved over WiirtualBoy. Most games now run at 100% speed without frame skipping. These improvements are due entirely to Ryphecha (Mednafen) who optimized the core emulation code in addition to eliminating idle loops on a per game basis.

Changelog
0.1 - January 13, 2012
Added support for MegaDrive/Genesis.
Added rewind support for the following emulators:
GameBoy/GameBoy Color
Game Gear
Lynx
Nintendo Entertainment System (excludes FDS games)
Neo Geo Pocket
PC Engine/TurboGrafx 16 (excludes CD games)
Sega Master System
WonderSwan (excludes large SRAM sizes: Dicing Knight, Judgment Silversword)
VI + GX scaler (eliminates majority of scaling artifacts).
Default screen sizes per emulator (1x, 2x, Full, etc.).
Full widescreen support
16:9 correction option (displays 4:3 on widescreen displays).
Double strike (240p) mode support (can be enabled globally and per-emulator). By default, is explicitly disabled for handheld emulators.
Color trap filter (Eke-eke implementation)
Master system FM sound support (when region set to Domestic/Japan)
Virtual Boy SRAM bug fix (was not being persisted).
Fixed bug where screen sizing controls were not being properly rotated (games with vertical orientation).
Ability to map "rotate screen" button for WonderSwan (Klonoa, etc.).
WonderSwan control mappings now supports "profile" toggle. Allows for saving mappings for both orientations for a single game (Klonoa, etc.).
Updated Game Gear to display with proper aspect ratio.
Ability to set Volume globally and per-emulator.
Additional SMS/GG compatibility
Fixed bug that prevented certain Ogg Vorbis files (multiples of 1024, go figure) from loading as part of a CD image (CUE sheet).
Fixed bug that prevented some FDS games (Metroid) from properly flipping the disk.

http://code.google.com/p/wii-mednafe...dnafen-0_1.zip