As a front-end engineer who used to work on Bloglines and helped create the Bloglines Beta, I say good luck! Your UI is very much like the Bloglines Beta and I realize this probably took a lot of work. Your challenges will probably be maintaining read state, security issues with trusting content in feeds, and keeping crawlers running so you don't miss items, searching content, handling archives, and more!

And of course, there's no money in this and the use of feeds are declining (so integrate Twitter and Facebook API).

Anyways, very nice. :)