I'm playing with a pre-Cardinal (the next Big Release) build of Flock, and man is it nice! They've replaced the blog editor, and it's the best blog editor I've used. Very nice. The blog manager topbar appears to have disappeared, but I assume it's just being tweaked and will return before the Big Release.
My only gripe is that category selection still sucks - no way to easily find one of my 331 categories in a list sorted by primary key of the category database record. Some sorting/searching/filtering/text-auto-complete interface would be waaay more effective. Oh, and the selected category didn't get applied anyway. I'll go in through the Wordpress web UI to fix it...
The Flickr interface is great, too. Uploading stuff, browsing people and tags. I'm really looking forward to using the native del.icio.us bookmark manager as well - the web-based one used by the Firefox extension is so slow it's actually painful to use. Cocoalicious works great, but needs to be installed and running in order to be faster than the FF extension...
Update: Wow. This build of Flock has a cool add-on, where it recognizes any image hosted by Flickr, and adds a contextual link to let you easily browse that person's photostream. Something you could do otherwise, but it takes 2 clicks, and goes through Flickr's site. The Flock feature uses their cool photostream UI instead. Very cool.