Something like this would be nice and could be easily modded in. I don't see Bethesda adding it at this point.
However, since stuff we put on the ground stays on the ground, it would not be too hard to come up with something that we could stack or place there that could serve as a marker. Perhaps some Alchemy Ingredients or Food Items arranged in a certain way. That is if the Physics of the game will let us arrange things.
Oh, certainly. Mostly just thinking out loud. I've been stupidly bummed since he bit the dust.
I did drop flowers and gemstones around his poor self and visit from time to time. His body is gone (dragons? wolves? heh) I'm going to drop an amulet of Mara there as well.