Ok, I know I was curious and I figure there are others who haven't been able to get any sets with the new horses in them; here's a comparison so you know what to expect:
Side by Side I give you the New and Old Lego Horse:



The biggest difference I see, outside of the 'shapely' design is that the new horse Does stand on it's back legs without assistance and it's head is wider than the older one.
The saddle is the same, the horse's blanket fits the same.
So there you have it!
You can be sure that my Lego stables and kingdoms will have both designs ... after all the new one can be for speed, while the old one for endurance. I think they'll work great together.