I'd still probably buy it if they made a cartridge version. If they just released a ROM... eh.
I'll just come out and say it: I would buy it from Wii's VC (or equivalent emulation). YES, I would.
In fact, one of the saddest things is that companies haven't been exploiting the niche markets for downloadable titles.
In the future, I suspect, smaller companies, or at least divisions within larger companies, will focus on "special markets" and tap into the $$$'s out there.
Then, of course, I'd be able to play FM Marty Splatterhouse and X68000 Rayxanber on my North American XBOX 720!!!