Obviously, an important thing to look out for is whether Pawlenty will take any shots (veiled or overt) at Romney on his home turf.
In the past, Pawlenty has criticized the Massachusetts health care reform, though without naming Romney directly. That plan's distinguishing characteristic is an individual mandate for people to purchase health insurance, combined with subsidies for lower earners -- that is, the same fundamental mechanism as the federal health care reform that Republicans now call "ObamaCare" and attack as socialized medicine.
Romney has tried to deflect this issue by differentiating his state-level program from a wider federal government approach, as in a recent speech: "Our experiment wasn't perfect--some things worked, some didn't, and some things I'd change. One thing I would never do is to usurp the constitutional power of states with a one-size-fits-all federal takeover."
The Tea Party faithful may not too receptive to that line, however. Their invite to Pawlenty, another GOP contender, certainly suggests that will be the case.