Many pundits have already grown complacent in their assessment of the GOP field as essentially whittled down to three, but former Bush advisor Karl Rove contends that that assessment, while accurate for now, might not hold over the long haul.

“We’ve got a good field,” Rove said last night on Hannity. “I don’t think it is the end, though, of the field. I think we are likely to see several other candidates think seriously about getting in. … I think Palin is gonna seriously look at it. … [She] has got a pretty active schedule in September. … I think Chris Christie and Paul Ryan are gonna look at it again … I’m starting to pick up some sort of vibrations that these kind of conversations are causing Christie and Ryan to tell the people who are calling them, you know what, I owe it to you, I’ll take a look at it.”

As Rove pointed out, all three technically have more than enough time to make a decision — Nov. 22 is the first deadline to secure a spot on the ballot. And, at this point, all three have a better idea of what, exactly, they’d be up against. With Tim Pawlenty out and Rick Perry in, the race of governors looks far different than it did a week ago. It can’t be lost on Christie just what an advantage his governorship in a blue state like New Jersey would be in a match-up with Perry, for example. As Ryan watched last week’s debate, he must surely have been struck by the lack of any substantive discussion of entitlement reform. No moderator of a debate that starred the architect of the House budget would have failed to ask an entitlement question.And Palin continues to engender more excitement than any candidate currently in the field with the possible exception of Perry (as the mob that followed her at the Iowa State Fair last week proves).

It’s easy to see how Rove might be right (that must surely make Ann Coulter happy!). But his commentary also doesn’t change that both Christie and Ryan have explicitly balked about a 2012 presidential run — and with good reason. Christie seems content as governor of New Jersey — and continues to achieve meaningful results and attract national attention there. Ryan’s budget has been a liability for other GOP candidates (albeit inexplicably to me — that’s as much the fault of candidates who can’t quickly and easily explain the need for entitlement reform, which they ought to be able to do), so it would surely be a liability for him. Plus, he’s young, the sort of congressman who, with a few more years under his belt and maybe some experience outside the House, will have achieved true “statesman” status. He seems to have all the raw material of a president, but the time is not quite right.

Unlike the other two, Palin has never explicitly said she won’t run for president. Instead, she’s led reporters and followers on a chase of epic proportions. That’s been effective at accruing headlines, but it also leaves little more to be dissected. If she’s going to run, then the “One Nation” bus tour was arguably a well-organized and worthwhile prelude to her campaign. If not, then it was a heart-warming exercise in patriotism that was nonetheless exasperating for its timing — clearly aimed to inspire ongoing speculation about a presidential bid (which I’m all too happy to oblige, it seems).

(Rove’s comments about the potential growth of the field start around 3:00. But don’t miss Romney toward the beginning of the clip just lighting into Obama for ducking out of his presidential duties to “campaign” in the Midwest and vacation in Martha’s vineyard.)

Update: National Journal reports Ryan is not considering a presidential run. Frankly relieved. He does too much good in the House — we need him there now more than ever.