Yes they are. In fact, they've been dating for almost 3 years! They started in August of 2006, on the break between Season 1 and Season 1.5 of Psych. :)
He has been dating Psych co-star Maggie Lawson since 2006. He will guest host along side with Dule 언덕, 힐 the January 25th edition of WWE Monday Night Raw