It should be really useful to spray tiles to randomize tilemaps with different tiles. I know we can use scripts for automatic tiles patterns, but still. I consider this an ehnancement.
Also Jumble tool will be really useful for Tiles mode — to randomly mix tiles (like Indexed).
Even Gradient tool may be useful to fill tiles gradients. I don’t tell about Inks =)
As for Blur tool it could only work if you calculate average color of tile (including alpha) and then average tiles according to this average color and selected range of tiles in Tiles panel (or all tiles if no range is selected). Fancy feature, but still has its meaning