It's supposed to be a hidden skill, and I've seen some people claim that eventually you can make more than just the wooden horses, but I'm just getting horses. More than that, I'm getting weird price differences based on who makes the horses. My Jacoban priest (Levels 1-3 during the quest) made a few dozen and every single one was worth $10. I had my Sorceress Queen (level 10) make a handful, and one was worth $18, but all other were worth $10. I had her make a few more in different areas in case buffs helped, but all others remained at $10.
Then I had my bard (Levels 1-4 during the quest) make a few. And right away I'm getting all sorts of different values. Some sell for $6, some sell for $20, and after a while he even starts getting ones that sell for $40. And apparently the prices change over time since I pulled out 4 selling for $40 and when I picked the pile up in his inventory a few minutes later it was worth $174 instead of $160. He's made more than 100 little wooden horses, but nothing else.

Did anyone ever get anything other than horses? Is pricing effected by buffs? Traits? Jobs? Human sacrifices?

I don't know if you are still checking back for replies, but I wanted to let you know that I have been trying to test this out lately.
So far my sim has made nearly forty wooden horses. I checked what mods I had for cheats, but there doesn't appear to be a hidden skill for whittling--perhaps that was planned for the future. All of the internet searches tell me that there seemed to be plans for additional objects...
I also did some brief searching in some of the Delta and Full Build files with S3PE. I have not yet found anything other than the wooden horse object, but as I said, I only trawled through the files briefly.

Probably just the horse then. I'm disappointed in whittling then. The horses can't even be played with by the kids.