Horses will in (90% sure of it), Bethesda just follows the "If it ain't implemented right now, don't confirm it no matter what!" policy. If you followed OB development from the very beginning you would know why they are doing this (a lot of stuff confirmed to be in ended up not being in).
Yes, it's a very safe approach for development right now. Even so, if they weren't implemented, it's because of priorities. People just take for granted that things are easy to implement because they can write up a quick summary of the concept or something, I swear. I'd rather see no Horses in the initial release if it means we get all the kinks ironed out from the currently confirmed features.
Having something to a degree was his favorit answer to almost everything in that podcast. There were horses in Oblivion and other fan made rideable creatures and they were pretty decent. Good enough to prefer having those over having nothing at all. Another modder (modder = hobby developer) made a rideable dragon for Oblivion, so how can it be there are no rideable dragons in Tes V? Has been done in several other games years before.
Honestly some things I heard on that podcast made me rather think those features were not even planned to be in this game and just taken into consideration cause guys like me keep ranting about it all the time, lol.
Just because it was in a previous game doesn't mean it 1) has to be in the next and 2) mean it will be implemented in the same way, which is what Todd mentioned. I agree, I'd rather see horses done well than the robotic feeling they had in Oblivion. Also, are you really trying to defend ridable dragons? It's not lore friendly, especially not for the sake of Skyrim. Just because a modder does it on pre-existing software with all the necessary components available for them doesn't mean jack. Developing a game =/= making a mod.