Mike actually raised this point (the final one, that is) at our editorial meeting last week. From First Read:
By the way, if the Democratic Party is going to start uniting around Obama as it began to do late last week during the spat with McCain and Bush, the Obama camp might want to make sure that everyone’s working off the same talking points. Here’s Joe Biden -- a potential Obama veep pick -- talking yesterday on ABC about Obama’s position on meeting with unsavory world leaders: “This is a fellow who I think shorthanded an answer that in fact was the wrong answer, in my view, saying I would within my first year, it implied he'd personally sit down with anybody who wanted to sit down with him. That's not what he meant. That's not what he has said since then for the last year or thereabout. And so I think he's fully capable of understanding of what's going." The “wrong answer”? RNC jumped all over that Biden comment. There are a lot of folks in the Dem Party (including the Clinton campaign) who believe Obama made policy based on a debate gaffe, because Obama's campaign at the time didn't want to concede they made a mistake on such a crucial question.
My sense is that Obama surprised his own staff when he said he'd meet with dictators during that debate, though they basically defend the idea now. Since then, he's become a little vaguer--he tends to stress negotiations with adversaries rather than face-to-face meetings with the likes of Chavez and Ahmadinejad--but obviously the McCain campaign isn't going to let him elide the issue. The question is, will he have to walk back the meeting idea and admit he overstated his point? Or will he stick to his guns? Both options could give McCain a valuable talking point.
Update: Ben Smith has the latest back and forth between Obama and McCain on this. In Oregon last night, Obama didn't quite say he'd meet with Chavez and Ahmadinejad, but he did talk about negotiating with our adversaries, and he prefaced his comments by invoking Kennedy-Khrushchev, Nixon-Mao, etc. Then, this morning, McCain hit him for being naive about what a summit with Ahmadinejad would mean.
Here's video of Obama's comments, but I can't get it to work.
Update II: I should have posted this initially. It's the transcript from an Obama press avail last Thursday in which he got a question about this same issue. (The Obama campaign sent it out yesterday.) I think he did a pretty good job with it here:
Asked whether his idea of meeting with hostile nations consisted of "from the get-go of the President of the United States" or lower level aides, Obama said, "The latter. Understand what the question was. The question was a very specific question. Would you meet without preconditions? Preconditions as it applies to a country like Iran for example was a term of art. Because this administration has been very clear that it will not have direct negotiations with Iran until Iran has meet preconditions that are essentially negotiations with Iran until Iran has met preconditions that are essentially what Iran used and many other observers would view as the subject of the negotiations. For example, their nuclear program. The point is that I would not refuse to meet until they agree to every position that we want. But that doesn't mean that we would not have preparation, and the preparation would involve starting with low level-lower level diplomatic contacts, having our diplomatic corps work through with Iranian counterparts, an agenda. But what I have said is that at some point I would be willing to meet. And that is a position, I mean, what's puzzling is that we view this as in any way controversial, when this has been the history of U.S. diplomacy, until very recently. This whole notion of not talking to people, it didn't hold in the ‘60s, it didn’t hold in the '70s, it didn’t hold in the '80s, it didn’t hold in the '90s, against much more powerful adversaries; much more dangerous adversaries. I mean, when Kennedy met with Khrustiev [sic], we were on the brink of nuclear war. When Nixon met with Mao, that was with the knowledge that Mao had exterminated millions of people. And yet we understood that we could advance our national security interests by at least opening up lines of communication. And this was bipartisan. And it's a signal of how badly our foreign policy has drifted over the last eight years; how much it has been skewed by the rhetoric of the Bush Administration that this should even be a controversial proposition." [Obama Press Avail, 5/15/08]
Emphasizing the distinction between "preconditions" and "preparation" may be Obama's best response to the GOP line of attack, though it requires a little more explaining than you'd like in the heat of a campaign.