Navagon: Well, unlike Steam, people know GOG will put the effort in to make sure the games work.
Yeah, I didn't bought many games on steam because there I know they aren't patched to the last version and to be compatible with mods, with known bugs and people asking "please, please patch it" in the forums. It's just ridiculous in some cases.
Navagon: Which is why I doubt either will make an appearance here. Sega is a strong contender as they've been releasing console versions of their Megadrive titles for some time now. Atari has also released some arcade classics in the past and they're already here.
Like Atari, Commodore is a completely different company hiding behind the name. But they do include old C64 games with their systems. So I guess there's some hope there too.
As for SNK - no clue. Despite collapsing and forming a new company with the same name and staff, they still have their old IP. But then it's a Japanese company. In a bizarre twist, Japan doesn't seem to have caught up with digital distribution yet and subsequently refuses to acknowledge its existence.
I don't care much about sega 'cause I don't feel like paying $4,5 for each game. If it was lower, then yes I'd care...
Atari, C64 and Amiga are the best bets, IMO. And dreamcast, since now it will be on PSN/XBLA.
Japan is really a weird place, looking by the whole picture.
They sell the best tech, they create the best tech, but they don't use it or they restrict it to the maximum. They don't use digital distribution like they could. There's also a lot of blu-ray movies I've heard that aren't released there, and this is in the land where the best blu-ray player in the world has its parent company, Japan.
Enough for the off-topic, hehe.