Flock hit beta 1 (or 0.7, depending on how you count) yesterday, and it seems like a really solid release. My favorite feature isn't even part of the core Flock code - it's got more Extensions enabled, including Mouse Gestures!
I'm hoping they nailed down the nasty memory leaks that plagued previous builds, and cleaned up the window opening code, which could take several seconds to spawn a new browser window. But it's definitely on the right track.
Now to see if they managed to squeeze in category sorting/filtering in the blog posting interface (which, other than that, has been the best blog posting wysiwyg interface I've ever used).
Nope. It doesn't sort or filter categories. Meaning that although it only took me 2 minutes to write this simple post, it'll take at least that long just to select the proper categories from the menu provided...