The biggie, at least from my viewpoint, is the tagging. Feedly has always supported saving articles for later, but you just end up with a huge pile of items. Finding that really interesting piece on running a startup from last July can be tricky with no way to organize items except chronologically.
The other thing missing here is that you apparently can't assign tags using Feedly's excellent keyboard shortcuts. If you're used to plowing through articles using the keyboard shortcuts, you'll still have to slow down and get clicky to add a tag.
Tags are private now, but expect more goodies based around tagging with Feedly 9. According to the F8 announcement post, with Feedly 9 you'll be able to "selectively publish and share your collections." Sounds just a little like the old days of goodness with Delicious, before that service was sucked up and derailed after years of neglect by Yahoo. (Not that I'm bitter or anything.)
Feedly has always had a number of different "views" you could use to browse your feeds. With Feedly 8, it adds a card view and a new titles view that displays more information for each item. The card view calls to mind a set of index cards, with the text-only posts just having the item title, summary and byline/publication info. Posts with graphics display all the summary info plus a random graphic from the post.
The so-called infinite view comes into play when you have a lot of items in your feeds. Instead of stopping at an arbitrary number of posts, you can simply keep scrolling through items as long as you have more posts to read.
If you haven't tried Feedly before, this would be a good time to check it out. You don't need to have a Google Reader account, there's a default set of feeds you can skim with Feedly even if you're not signed in. But I do recommend using it in conjunction with Google Reader. Note that Feedly syncs in real time with Google Reader, so changes made in Feedly should reflect in Google Reader as well.
The update is available immediately for Chrome and Safari, but the Firefox version is currently under review. Note that you can still install it, but you'll be warned that it could "harm your computer." For the cautious, I've installed Feedly 8 and thus far my computer seems unharmed.