I hope the horses in Skyrim are as good as the ones in Shadow of the Colossus, that's the only game that I think has successfully made the horses behave as living things, so if for example you ride Agro on one of the forest like areas he of his own free will, will avoid trees and jump when needed he also would walk slower and with more caution when the path would become more narrow witch makes it look as if hes reading the environment, or stop and retaliate when you try to jump on a clearly deadly pit, you control it like a real horse, that's the stuff Skyrim needs, the horses on most games are more like cars, they just move into the direction you click, witch make the whole thing very unnatural.

http://www.youtube.com/watch?v=xc9GoOObsmc&feature=related

Or like the horses in Red Dead Redemption. The detail they put into the flanks/muscles was pretty cool and realistic.

Yeah that looks nice. And so does RDR horses: http://www.youtube.com/watch?v=bWc_hRPjWXg

Both have nice horse animations, but RDR being more realistic.