I've been preaching not just testing landing pages, but testing goal funnels and assumptions of where to send the traffic (that was the entire topic of my Pubcon presentation this year).

I often see that the 'conventional wisdom' best landing page isn't true in some cases – why you test; and one of my posts here: http://certifiedknowledge.org/blog/landing-page-testing-are-you-sending-traffic-to-the-correct-page/

Here's a quick fast read that also look at that importance.

Nice post. There's an excellent graphic of a person's search process, keyword refinement, and different sites visited throughout their buying cycle.