Yeah i'm not sure either about what's their goal with the Steam release, but i definitely think it's an interesting development and i'll be following what's coming next.
As someone else pointed out, there are already some emulators suites on Steam (like the New Retro Arcade Neon) so maybe it's...
I don't think that ever happened with Nintendo's stuff but the Sega Genesis games on Steam and the Neo Geo (drm-free) games on Humble Bundle definitely give you the rom in a folder without hiding it or anything.
My favorite genre is 2d action-platformers, i guess that the first Mega Man X Legacy Collection would be a pretty good starting point since it nets you 3 masterpieces (and another cool game) for only 20 dollars, imho it's one of the best bang-for-bucks deals around.