I’m not surprised, considering they have slowly included almost every little Twitter nigglet there is. What does surprise me however is that they decided to make it a hovercard instead of a panel. With interaction moving towards swipe/flick gestures and touches, there has been some talk recently about the end of hover as viable interaction gesture. I use Facebook’s full site on my iPad, and won’t get any benefit from these hovercards. The same goes for Twitter, but I won’t complain because I use it mostly from apps. Facebook doesn’t have that luxury, and frankly, it doesn’t need it. I’ve always liked Facebook’s UI. They’ve made their interface as simple as they probably could given the amount of features they have.
I’ve never been a big fan of hover, always reserving the gesture to show more information, not to show or hide controls or change something. It’s too fiddly to code (don’t get me started), but it’s also fiddly to use. Ever seen that two level deep menu disappear because your mouse went just a little too outside its hit-radius? Clicks are much more deliberate, and can be treated as a solid statement from the user saying “Yes.” I like that; knowing that the user really did mean to do what he did. If you want some fair advice, don’t use hover for anything beyond showing information that the user doesn’t really need if you can.