It reflects Lightning. At least in an experienced user's hands. It's a style/state-of-mind. Like Juyo combined with a mental Force setting (in this case a borderline Dark Side setting).
The position still begs proof. The textual support that Truejedi gave convinced me that it may be possible, but your still going to have to show why your interpretation is correct as opposed to mine.
It's also a literary device to explain why Mace was the only movie-character shown to actually reflect Lightning in a similar manner as a blaster bolt, instead of pooling it in his palm like Yoda.
Mace was also the only movie character in the position where he was being bombarded by a continous stream of lightning, at close range. Obi wan just blocked a short burst when he was fighting Dooku, not to mention if you watch the two scenes Palpatines lightning is *much* more powerful. So if you take all those factors together, Dookus lightning would of dissipated a lot more easily.
And if you watch the scene again, notice that initially the lightning is just being blocked, with arcs going out in all kinds of directions but not at Palpatine. Then Mace moves his lightsaber forward, and angles it at Palpatine, and only then is it being reflected into Palpatine. This is pretty damn conclusive evidence that the angle and position of the lightsaber was the reason for the lightning being misdirected. Remember that in the case of a conflict, the movie takes precedence over the novel, although I havent seen evidence that a conflict even exists from your side of the argument.
As far as Yoda is concerned, thats not comparable because a lightsaber wasnt even being used. Yoda was using the force to stop the lightning and then throw it back at Palpatine. As we all know, if Mace didnt have his lightsaber he would be totally screwed.
"Before he could follow through on his stroke, however, a sudden arc of blue plasma sheared through his wrist and his hand tumbled away with his lightsaber in it. Palpatine, suddenly alive with power again, roared back to his feet and lightning speared from the Sith Lord’s hands, and without his blade to catch it the power of Palpatine’s hate struck him full-on."
By the by, I love Picard pics. I lol'd enough to steal that one.
Yep Captain Picard owns. You had the honor of receiving one of my best pics.
EDIT: It's been a while since I read any SW novel, but I think it's stated somewhere that Vapaad not only acts as a foil against another Dark Sider, but bolsters one own inner-darkness into physical (and I guess general) strength and power, without actually succumbing to the Dark Side.
I believe I already posted that quote for you when I responded to Truejedi. It is true that Vaapad channels dark side energies in order to give the user strength. However, saying that Vapaad acts as a foil against another dark sider lacks evidence. Unless you have something else to give me.