The NES and SNES Classic were just cheapo X games in one, except they made sure they didn't suck. Plus they were super cute and small. What you guys are really talking about is a new system that's backward compatible.
I think it would be totally awesome if Sony made a "classic" system. I think it would be even cooler if they didn't just do it through emulation, but put a new upgraded processor in there, a flash drive, and a digital store with the ability for companies to get their games on there. Let companies come out with brand new games for a new, improved, but low cost, PlayStation Classic.
Of course, they could also just hype up what's essentially an emulation system, and then release a severely limited number so people practically riot, and pay insane prices for them on ebay.