Wow, I'm really enjoying using this, slick looking too. I really like all the little touches you've added, the UX is great. I think you've come the closest yet to the simplicity that google reader offered. I would try as hard as possible to maintain the feeling of simplicity in your design even when adding more features.

A few feature requests, feed importing, profile editing and a larger feed view (maybe collapse the sidebars?) also folders to be able to sort feeds you've added and the respective views.

edit: updated some things