I don't mind 2.5D, but at the same time, it's nice now and then. I would love a sprite-based Mario to see a sort of eShop release, though. Maybe Nintendo could de a series of "sequels" to their classics (SMW, SMB3) that are essentially the same with graphics and game mechanics, but with SLIGHT updates to the powerups and mechanics and such. It would be almost like DLC for NES and SNES games. lolYou know what I REALLY want. A 2D mode with Sprites as dynamic as the 3D models. I hate 2.5D to be honest, its a purely graphical change and it pisses me off since Nintendo says they dont focus on graphics. Like, I hated how Mario looked in NSMB, after I got into the hacking scene I looked all over the net for some kind of mod that would make him a sprite. In Smash Bros its alright since the characters are highly detailed and very fast. But IMO 2D platformers should be 2D platformers. Not some 2.5D crap.
I completely disagree with Zantiago and agree in some points with xwatchmanx.
I think that mario sidescrollers becoming 2.5D is a change that will last forever
I think it would be pretty good, and think someday Nintendo will releases Super Mario World and/or Super Mario Bros 3 on Virtual console on e-shop.
But I think, if Nintendo release a sequel of Super Mario World o Super Mario Bros 3, they will release them in 2.5D sidescroller