Many of these recommendations are fairly hard core jazz piano, and may not be as accessible to a rock fan. Don't want to scare you off right away. Jamie Cullum is nice jazz piano without going over the top. I would suggest a few others that are a bit more accessible and less hard core, like:
David Benoit
Diana Krall
Claude Bolling
Then move up a notch to:
Vince Guaraldi
Michael Petruicianni (may have spelled it wrong)
Bill Evans
Dave Brubeck
Jackie Terrasson
Marian McPartland
Then you can try harder stuff by:
Herbie Hancock
Kieth Jarrett
McCoy Tyner
Chic Corea
Oscar Peterson
Enjoy,
Bob
David Benoit
Diana Krall
Claude Bolling
Then move up a notch to:
Vince Guaraldi
Michael Petruicianni (may have spelled it wrong)
Bill Evans
Dave Brubeck
Jackie Terrasson
Marian McPartland
Then you can try harder stuff by:
Herbie Hancock
Kieth Jarrett
McCoy Tyner
Chic Corea
Oscar Peterson
Enjoy,
Bob