The 14 celebrities taking part in the BBC reality show were announced on Monday and include Girls Aloud star Kimberley Walsh and Olympians Louis Smith and Victoria Pendleton.
Commenting on the lineup, Horwood said: "I think Richard Arnold is going to be absolutely dreadful.
"It's only because of his campness that I say that. Also he's an ITV presenter!"
His picks for potential series stars include CBBC actress Dani Harmer, presenter Fern Britton and Kimberley Walsh.
"For me it's Kimberley Walsh at the top, I think she'll win," he said.
"Only because she's danced before. She's foxy and she's hot, she will do very well."
Strictly starts on Saturday (September 15) night at 6.30pm on BBC One.
Photo gallery - Strictly Come Dancing's celebrities: