I know of Ashley Roberts. She used to be on another dancing show, as a judge, (can't remember the name) with Ashley Banjo from Diversity. I think she also used to appear on Ant & Dec's Saturday Night Takeaway thingy.
Although I don't watch it, I think dancers should be excluded because it would be fairer to have 'celebrities' with no experience competing. That way there is no advantage and viewers can see what progress each of them makes and therefore (in my opinion) it would be fairer for everyone.