| I haven't had much chance to play recently, but what I have thought about, and wanted to share is an idea of putting the skill challenge in a tree-structure.
You have your starting point (first segment), and depending on whether your players fail/succeed at the first segment, they will end up in a new situation.
For instance, the characters are being chased through a city by a gang of thugs. A success in the first segment will change the "scene" to the busy marketplace, where new skills might be viable (acrobatics for dodging villagers), or a failure might mean that they ran into the thugs "home turf" and more thugs are after them. A success at the marketpalce might mean the characters run into a group of the city guards (which might open diplomacy options?) that might help them in a battle, or another failure after the first might mean that the characters make a wrong turn and are trapped in a dead-end alley.
By no means does a failure in a segment have to turn into a worse situation or vice versa (in the example above, no character might be trained in either acrobatics and diplomacy, and will have a harder time even though they succeeded in the first/second segment).
All this means some more work for the GM of course, but some scenes might be able to be re-used.
I didn't mean to derail the thread from Stalker0's suggestions/proposals above, I just wanted to share my idea.
My biggest issue currently (though an issue with skill challenges themselves, not Obsisian) is the diplomatic challenge where all the players take turns trying to come up with something to persuade their target. It seemed a little forced to me when we ran it. | 
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