According to the Radio Times website, today's show features "reality star" Bobby Cole Norris (from The Only Way is Essex, according to Wikipedia), Duncan Preston (from Emmerdale) and Kimberly Wyatt ("former Pussycat Doll").
No, I'd never heard of them either but, as I hardly ever watch telly (and certainly not so-called 'reality' programmes or soaps), that's probably not too surprising!