Yeah, he's entered with Liezel Huber.
(that's Liezel Huber, World #1 Women's Doubles player).
Huber's his partner at every grand slam, bar Wimbledon. Gotta be honest, though, she cost them a final place at least year's US Open. She was horrendous.
Still, being paired with one half of the top female doubles pair obviously speaks a lot about Jamie's ability.