I spotted a link to this article in Mearls' twitter flow . . . .

http://awesome-gaming.blogspot.com/2009/07/using-d-4e-skill-challenges-i...

I'm intrigued by the idea -- although I think it needs some serious fleshing out.  I'm going to be keeping an eye on these guys . . .

Actually, though, I want to think about trying to use something along these lines in my next game session -- I have a little over a week to plan it, so I have some time to chew on it.  

Seriously, though, these sorts of challenges seem like they would make the most impact in the game -- and be the most engaging for the players -- if the players are the ones coming up with the countermeasures on their own.  And that's going to be the trick. 

They need to be taught that countermeasures are possible.  This is a big one -- and it means that you're going to have to hand-hold them through several of them until they get the idea that coming up with creative ideas will pay off. 

They need to have the ingredients.  If there's a chance to restrain a dragon, make sure you describe the pile of coiled rope in the room.  The PCs will latch on to whatever details you give them when you describe the room, especially if the combat seems very difficult -- what can they do to handle the issue? Rather than just telling them what they might try to do, give them a stack of clues and see if they piece it together.

more on this ....