I like it, I think people will adopt it if it was a Chrome plugin that converted Gmail into this UI. Their infrastructure and your skin. You could charge for some features for power users that Gmail does not have.
I like your idea as it would eliminate a few of my "bottlenecks". I will check out if a chrome plugin might just do that, OR even see how http://www.streak.com/ accomplished their goals. Haven't looked into that, yet.