Just look for an emulator in SDL and you could try to do it yourself.
I believe the problem so far is zsnes, which is in sdl, requires x or is required to be compiled to use svgalib, both of which I believe are not something easily done/possible in Pre. Though I could be wrong (but if it was easy it would already be done).
while I am for it, I found playing the GBC roms on VBA to be a pain. Games like Super Mario Bros and Donkey Kong Country are my favorites but the small keyboard discourages the use of simultaneous A & B (for breaking into a run and jumping).
Infact I also felt many times that the Pre's keyboard is too delicate to take such hard use.
I feel once the PDK is out in full swing, developers for the iPhone that have already created emulators. I could see them getting ported if the interest was shown.
Forget SNES. I want to play some Neo Geo! The SNES had the top shoulder buttons that would be a pain to use but I am really surprised we do not have Little John Palm (LJP) natively supported yet.
But yeah... SNES emulation and a whole lot more should be out quickly after the PDK update. We should even see emulators in the official App store due to Palm's official support of it! That's a first for smartphone platforms, if I'm not mistaken.
It's sad, my zire 72 was much better for the games I enjoy playing than my Palm Pre. I loved using the D-Pad for playing Super Mario World. I know LJP works in classic, but I don't think SNES does, and the keyboard isn't as good for those types of games as I originally thought.