Not an easy answer. I am never one to re-write history, and I believe that people should be reminded once in a while that history is not always pleasant.
But if the man is sprouting fungus, and the area is in a state of disrepair... someone should do something.
I remember the guards at Lenin's Tomb. The way they marched, the way they held their rifles for ceremonial drill (fuck man that would suck, I thought Canadian drill was tough) and the way they had to LOOK a certain way. You were chosen by your physical features as well. Imagine someone doing that in the good ol' US of A. "Sorry son, but you don't look 'Marine' enough to do that duty..."
If the Tomb is a symbol of what is holding Russia back, then maybe they need a symbolic change. I say move the body to a more historically appropriate place, like a national museum, or the first place he made a public speech, or the first place he massacred his dissidents!
JK on that last one