I believe the emulators are part of each game for download, so they are probably specifically tailored to each game, and only emulate hardware, mappers (NES), and other specific things that are needed for the game to function... Leaving you with probably an emulator good enough only for the "ROM" data given to it.
Even then so, you have to reverse engineer the encryption or whatever DRM is on the game; I don't believe anyone has done this yet (or at least they have not published their findings anywhere), go google "wii vc hacking", you'll find cracking RSA isn't exactly easy.
After you do that, or hack VC to run unsigned games, you still have to work out the format of the ROM data stored, which is probably the easier part out of the whole sequence.
So at this stage, "no", but not necessarily "never" either.
For the time being, there's always the GCN alternative.