Nadal v. Soderling - 4th Round
I'm betting on Nadal, but I think Soderling could make it interesting for a while (if he starts out well). He has the sort of big game to hurt Nadal and has the go-for-it attitude necessary for someone who can't outgrind Nadal.
I doubt he'll engage Nadal much in long rallies. If he's "on" it could be a fun contrast in styles. Then again if he's "off" and/or gets frustrated early, Nadal could run away with it.