Maybe I'm misunderstanding the question -- How would you track at the keyword level for PPC? You only know which ads are bringing in traffic for which keywords, and which combination of headline+copy+keyword+ad position=conversions.
With organic, you know which keywords are bringing in traffic to which pages, assuming you're using good analytics. And you can determine which pages might be better-positioned for funneling conversions -- the simple rule I use is, any page that gets substantially more direct-from-search hits than it does hits from other parts of the same site, and sends substantially more visitors to other pages on the site than it does away from the site, is a money page that needs to become part of the conversion process if it isn't already.
But where is the "keyword level" in that equation?
Frank