Yesterday a plugin update took down my entire site and I ended up uninstalling 2.7 and doing a fresh install of 2.7.1 then restoring a back up of my databases. I got all of my content and customization back, but my feed will not come back.
I deactivated the Feedburner plug in (as well as all plugins) and changed back to my default theme and default permalinks and finally my feed showed up, sort of. If I click on the feed, sometimes it comes up after about a 30 second wait and sometimes not at all. And thats too long of a wait for Feedburner to use.