According to the Wall Street Journal, he'll be jumping into the Presidential campaign waters in August.
According to the WSJ:
Our normally reliable Republican source reports that Mr. Perry has surveyed the field and decided to get in the race later this summer, perhaps around the time of the national prayer meeting that Mr. Perry is hosting on August 6 at a Houston football stadium.
Perry's people continue to say that Perry hasn't decided yet, so it's entirely possible that the WSJ could be wrong (wouldn't be the first time). Could we be so fortunate as to have Perry mixing it up with Romney, Bachmann, Cain and Pawlenty?