Aside from the immediate political families, it's not unfair to ask, 'Who cares?' As I vaguely recall, Pawlenty was a candidate for the job himself until he discovered not that many people cared about that either. He only has a $500,000 campaign debt to show for it.
We now await Rick Perry's fellow Texan, Kinky Friedman, to step up with an endorsement of anybody else in the field that might be a tad more thrilling.
UPDATE: Louisiana Gov. Bobby Jindal endorsed Perry. It's a whole new ballgame between Pawlenty and Jindal, if nothing else.