One of the more interesting presentations (so I've gathered) from the recent Blender Conference was a talk by Benjamin Walther-Franks titled "Performance Timing Tools". Although I haven't managed to find a recording of this to watch yet (it would've been on in the middle of the night here... far too late to watch realtime ;) I have managed to find the link to the the page for this:
From what I understand of these techniques from reading the link above and some of the linked papers, these tools are focussed on
decoupling the careful creation of poses and the timing of them. So you
start by blocking out your keyframes, and then use these tools to
roughly trace out the motion of a controller on your rig, "acting out"
the motion with the timing you intended. The tool then takes analyses
your acted out motions, matching up keyframes with parts of the motion
curve you traced out, and just takes the timing information of these
matched up parts to retime your keyframes. So it's kindof like a keyframing + mocap hybrid, which takes the strengths of both and combines them into a single technique.
This is very interesting stuff. Along with motion path editing (as first hinted at on the website of Reflex by DigitalFish a few years ago, and recently in Maya too), these belong to a class of approaches which aim to make 3D animation a more interactive process that occurs in the 3D view through direct manipulation vs more slider-driven GUI's off to the side.
Personally, I've been quite interested in this sort of work. Perhaps you might even have heard in passing that I have been planning some other tools that share some similar characteristics too, including some which I believe will make posing characters faster and/or probably more intuitive too.