I think alot of you fail to realise just how frustrating the original 8 bit games were. There were no dashes, double jumps or any other assisted moving except with your dog, Rush. If some spikes or wall comes down and crushes the last pixel of your toe you completely explode and die. There were alot of improvements to be had in the 16 bit and on games that the original nintendo simply didnt have. If we are going to talk about Guitar Hero, lets compare Guitar Hero 1 to Guitar Hero III, one was very raw and unpolished compared to III's features like hammer ons (even if they are too easy compared to II). Mega Man is the same way, how can you go back?
Now what *should* happen is Mega Man should make the jump to FPS, it would make an extremely solid first person shooter, with interesting movement mechanisms, the dashs and extremely vertical gameplay of the bosses fights would be very cool. Think of the Aliens in Aliens Vs Predator games, for a fairly good showing of what wall walking and grabs, and dashing can do in an FPS. Or even Gordon Freemans jumpkit thing towards the end of the first Half-Life.
Obviously Ive been anxiously awaiting a real, and well done FPS mega man game (I think there was one for N64 that was balls so Im ignoring it), and have basically designed the entire game in my head.