OK that's amazing... My brother and I had been joking about Clarabelle and Horace being everywhere, and wondered why they hadn't trotted out a Clara as well. Guess they beat us to it.
As to Horace and Clarabelle being staples since 2006, I think that's pretty nifty but also bizarre... wonder who was behind that? They had a huge queue when I saw them and I wanted to go down the line and poll everyone to see exactly how many people knew who they were. I can't imagine that many kids today would even have a clue, seeing as the Disney Channel doesn't even show Disney cartoons, much less the very old shorts that they would have been in.
My guess was that a lot of parents would wait until the characters signed the books, sneak a peak, and then pretend to their kids that they knew all along. "Oh, it's HORACE honey..." hehe
So when do we see Oswald?
In the early to mid 80's we used to have a Character show in Fantasyland that featured her called "Fantasy Follies"