First off, I really liked your letter to Mr. Lutz...well thought out and concise. And I am very surprised the Ute isn't going to be a Chevy El Camino...
BUT, moving past the history and emotion and trying to view this as a business decision -- if it's not going to Chevy, then my vote is for Pontiac. As Northstar pointed it, the Ute is still a CAR with a bed. And I'm also assuming the Ute would be imported in limited volumes from Australia, much like the plan for the G8. So RWD performance car sold in limited quantities, combined with leveraging the existing $100MM investment in turning the Commodore into the G8 and Pontiac makes the best business case sense. It combines the service training with the G8 service program as well. And Pontiac desperately needs the product...and might get the Ute in lieu of a Firebird. And best of all, NO BADGE ENGINEERING within the North American market!
Chevrolet will have the Camaro soon and could turn the 427 concept into a Silverado SS (may even be in plan). Not ideal if you've been wishing for an El Camino, but not too bad if you're looking to maximize your investment while providing differentiated products to your various brands.
Let's not forget the GMC Caballero Conquista edition! Also, Pontiac did build an engineering prototype of a Grand Am pickup using a GMC Caballero between 1978-1980. It's featured in the Aug 2007 edition of Smoke Signals magazine and resides in the GM Heritage Collection. So it's not exactly a new idea.
Cue Regfootball rant about RWD with no AWD option...