Should be changed so that it just drops off the username, without the avatar being mixed up in it. It's a bit messy at the moment.
ETA: meaning having an avatar as part of an h4 sorta sucks.
User interface-wise, it's good to drrop off frrom below the avatar.
I have to admit I agree with Ant (and that's scary): I liked it more dropping from the name.
I'm finding I like it that way. Problem with the earlier version was that the av was still part of the anchor, so it felt rather weird when you hovered on the av and this thing appeared and covered it. For my guinea pig, I've since changed it to having the drop just triggered by the username, with the avatar itself just doing the basic link to profile. I rather like it that way. It tends to fit better in the post, which can be good on a smaller viewport, and it doesn't feel weird to use. Also gives more layout options, because the avatar and username don't have to be chained together.