Merse, i dont think you quite grasp what would need to be done here.
We have 148 tilesheets (at 256x1024 resolution)
More tiles get made and added every day.
We most certainly do not need to change from 2D to 3D. A 3D 'tile' doesnt exist. It would need to be a 3D object. Making a mesh for a building is completely different to simply drawing a flat plane object in PS/GIMP.
I did most of this tile system, so please i think i know somewhat what i am talking about.
As for improving the clarity of the current tiles, this will most likely happen, but slowly over the life of PRO, we have other more important things for the artists to be working on (NPCs and other bits). And as the only artist specifically assigned to making and maintaining the tile system i am making sure we have all the images needed for the mapping team to do what they do with the skills they have, before we update the quality of the ones we have.
Updating the clarity and sharpness of tiles will happen though, believe me.