There's already thousands of e-books in ePub available on Feedbooks, and you can of course turn RSS feeds into ePub too using our service:
http://www.feedbooks.com
I'll do an official release for our sync software, I'll change my subscriptions to ePub once the firmware upgrade is available. Just have to plug-in my device every morning, and it automatically downloads all my RSS feeds to it.
Here's Mobileread in ePub:
