He all but confirmed it himself in his interview with Halperin, but this is the first hard “yes” to come out of his camp after weeks and weeks and weeks of teasing. It’s newsworthy if only for that reason, although I’m intrigued by the timing of the leak. Why not wait another 48 hours and let him end the suspense himself on Saturday? Are they a tiny bit spooked by Palin’s arrival in Iowa, maybe, and looking to preempt that with solid news about him running? Or is this all about ensuring that his name is mentioned at the debate tonight?

Texas Gov. Rick Perry will make “a definitive announcement that he is in the 2012 race for the presidency Saturday,” aides told Fox News.

The language is significant. For several days the Perry camp has said he would signal his intentions and announce later.

“This is it,” the sources explain. No exploratory committee, no more deliberation.

Speaking of the Halperin interview, Ace is totally right that Perry made a bad mistake in gossiping about the conversation he had with Latvia’s prime minister about Obama. It humiliates a sitting president who, like it or not, is in charge of foreign affairs for another 15 months and it humiliates the Latvian PM by putting him on the spot over what was, almost certainly, supposed to be a confidential chat. I think this is more a case of Perry being absentminded than deliberately setting out to breach that confidence, but he can’t let it happen again.

Via the Daily Caller, here’s Joe Scarborough dumping on him this morning for praying a bit more publicly than he’d like. Meanwhile, Tom Tancredo’s tearing Perry to shreds in Politico for being much softer on amnesty than he’d like. He’s too far right for the centrists and too far towards the center for the right — not a bad place to be for a guy trying to triangulate between Romney and Bachmann. Besides, if he and Romney do end up in a two-man race, does anyone think Mitt will be taken seriously if he tries to beat Perry by becoming some sort of table-pounding border enforcer? C’mon.

Update: More confirmation. He’s in.

Update: At Townhall, Dwayne Horner has more details:

Stories started surfacing earlier this week saying that Perry, the longest serving chief executive in Texas history, would use the conservative gathering to remove all speculation about a run for the White House. Sources revealed to Townhall yesterday that the Governor’s children, Griffin and Sydney, have been told to clear their schedules starting Friday so they could be “with their father at this special time.”…

With the confirmation that Perry will indeed be a candidate, speculation is that a formal announcement is in the works during Labor Day weekend in either Austin or on the Texas A&M campus.