This is probably the most important SEO news this month. It allows a simple way to improve SEO payout by improving the conversion rate of landing pages.
While in itself it does not generate more traffic, it helps to improve user experience and increases the “goals” (such as sales, bookings, subscriptions etc.)
It has an important side effect on quite a lot of services/companies with similar usability improvement goals. So, expect something similar to “analytics earthquake” and “maps earthquake” once tool is released (free of charge) to all interested webmasters.
Google adwords website optimizer is (at the moment) in invitation-only beta, but if I had a usability services company, I would be worried. Very worried…