I would like something like a tag cloud for my feed, so you can see the active tags and wander the posts that way. Would make such a difference keeping track of people you follow.
Also a bookmark system for posts that you found that you want to come back to or that had helpful information.
You can basically do both with Evernote for the time being (which is what I'm doing), saving the posts and tagging them, but discovery is still manual which is the problem.