If you can give a good use for this mob, such as being an optional AI competitor to the player that can build or mine within certain boundaries, I can see how this would be a nice suggestion. (The AI would have to not be a lag-machine, an annoying griefer or an easily exploitable mechanic. But that's another suggestion, for another time.) The old Steve never really did anything but wander around and act stupid, and I don't really think that it needs to be brought back exactly how it was in Pre-Alpha.
I get offtopic a lot, be warned. I also often mention a Minecraft clone called Minetest. The clone is nowhere near playable with it's default game in my opinion, but it's at least the start of a good open-source voxel rendering engine, and maybe one day it might be decently playable.