I would guess she'll announce some time in September, and she'll have a ton of grass roots support.
If she's the nominee, she'll win. If Romney's the nominee, we get (at least) 4 more years of Obama. If Perry's the nominee, it's a coin toss who will win the general.
I'm warming to Perry as a second choice, but I'm pretty sure that the Obama team wants to run against George W. Bush again, and Rick W. Perry would be a huge gift to them.
If you want to take that chance, that's your choice. I don't like the odds with Perry. Too soon after George W. Bush, and Bush is still way to unpopular and hated by the left. Perry will mobilize Democrats to defeat him more than most "Republican Strategists" are saying right now. Of course, the Party Propaganda Ministry (or is it the Ruling Class Propaganda Ministry) is pushing Perry right now because Palin and the TEA party scare them.
I'll stick with my advice, Read my lips, no new Texans! (and as a resident of Florida, please, please, no new Bush's either).
I would welcome her to the race. In fact, I have been impatient for her to get into the race.
Of course, I will still support Perry in that scenario.