That just made me think of Robot Chicken, like a skit where Palpatine is practicing and he's like throwing Force lightning curve balls because he was frustrated that Obi-Wan caught it on his lightsaber.
I'd like to think that the absorbing Force lightning skill is very advanced and you need someone with the length of training that Yoda had, to master it. Unless that power and Yoda knowing it, was common knowledge among the Jedi, I think they should have had Dooku look shocked and then panicked for a second before he deflected the return blast. That would have been even more awesome. I don't know why anyone would know Yoda had that ability because no one would have seen it used because the Sith were gone. It could also be an old technique that Yoda learned from some of the last masters who had actually faced Sith Lords in combat.
I think it could be a super advanced version of the energy absorption power we've seen in the movies (Vader deflecting Han's blaster bolts with his hand, yeah robot hands, but still...) and characters like Corran Horn in the EU who could absorb energy and then use it to "charge up" their Force abilities.
