Dr. Weird, NeoGeo roms aredecrypted on the fly. There is no reason to decrypt the roms or replace the encrypted roms with bootleg roms. MAME as well as Kawaks, and Final Burn Alpha, even Nebula all decrypt the graphics on the fly.

Darth, there is only that one that I know of, the SonED thing. About DS and PSP, there are emulators already out, but you must understand how emulation works. These systems are only partially emulated, and are ussually unoptimized. That translates to, all games are virtually unplayable.

The only system that was ever emulated well when it was still living was NeoGeo, and perhaps PSX. Ussually a system is dead from the market before it's emulated well, or it's been out awhile (GBA). Infact GBA is probably the last system of that kind. One that was able to be emulated very well so early on. GBA had no encryption, Nintendo DS does. Although it's already been hacked fyi.

Infact there are NES and SNES emulators out now for DS. And there is a GB/GBC emulator in the works. PSP is hacked too, with ports of PC emulators like Nester and Snes9X, and Dgen too I think.