Today at 12 noon Australian time the two presidential candidates meet for their third and final debate. With Barack Obama moving ahead in the polls, John McCain is expected to be on the attack, and has already said he’ll raise Obama’s association with former 1960s terrorist Bill Ayers as part of the discussion.

Here’s a roundup of pre-debate news, commentary and previews:

Debate Expectations. As Maureen Dowd noted on GMA: McCain needs a big rabbit out of a small hat… The Obama campaign is stoking those expectation with a memo out this morning entitled, “John McCain’s plan to “whip” “That One’s” “you-know-what.”” — Swampland, Time

What McCain must do tonight. McCain doesn’t need a “knockout” – whatever that term might mean – but he almost certainly needs to come away from tonight with a clear victory over Senator Obama that will help jump start his flagging campaign. A draw will not do. — RealClearPolitics

McCain’s tough task as 18 months of debates end tonight. Obama has used the past month to consolidate his support. He has been aided by the economic crisis but also by his own actions. McCain is now running against many opponents: the economy, public dissatisfaction with President Bush, the clock and a skillful rival. That’s a lot to overcome in one, final, debate. — The Trail, Washington Post

Bringing up Ayers might provide a dramatic moment tonight. I hope McCain puts it simply and directly, something on par with, “Why did you go work for a man who built bombs and killed people? How could you work for a man with blood on his hands?” Obama’s twin excuses — “this was a long time ago, I was only 8” and “Ayers isn’t just a radical, he’s also a brilliant reformer of education” won’t fly if it is put that starkly. — National Review

McCain’s Mission Impossible. His best bet, I think, is to angle for a memorable moment that reminds viewers of why they once liked him (and not why they shouldn’t like Obama). He can’t afford to “win on points” or (God forbid) “tie.” McCain’s “moment” needs to overwhelm tonight’s other 90 minutes. It needs to be ripe for endless recycling on cable news and YouTube. And it needs to be the only thing we remember tomorrow. — Stumper, Newsweek