Nah. No Melty in 3D would be as popular as the doujin game-like 2D looks. Also, there's no 3D game I'm aware of that shares a complex, fast and dynamic gameplay like even common 2D fighters, not to speak of Melty.
Especially BlazBlue, which was concepted as highres 2D fighter from the beginning, would not be that cool if it was in 3D. Even though it's a 3D engine and it uses 3D stages, the parts of it are still made in 2D.
Gameplay is a non issue, tho.
They could simply have identical gameplay. Heck, they could have MBAA running hidden in the background, but overlay the celshaded models where the sprites are located. Saying that a 3D game must have different gameplay to a sprite based game is simply wrong.
Now that 3D celshading looks almost like drawn anime, I think most games should go for it, because of the massive advantages that 3D offers:
- Less work /cheaper to animate many moves and characters (compared to hires 2D)
- Future proof, animations and models can be used in future hardware without looking awful, unlike sprites.
- Can easily do new costumes, share/trade animations, etc.
- Works better on modern hardware.
- Can do various effects impossible in 2D, like proper slow motion, camera changes, etc.
Sure, maybe you prefer sprites instead, but hey, if you can tolerate melty's 320x200 sprites, then you have to be a gameplay > graphics guy, right? So why not tolerate 3D instead, and let the game benefit from the advantages listed above?
Hires sprites are a dead end. Look at KOF12 - they spent all that money and effort and already the sprites look pixelated and kinda awful. And RAM / workload limitations means animations have far fewer distinct frames than something like 3S or Melty.