I had the same question. I found this page from bart, though, which somewhat clears up the thinking behind it.

I still really don’t see what all the hype is about with this thing: I have del.icio.us integrated into my browser now via the Bookmarks Bar. It won’t tell me when I’m on a page that I’ve bookmarked, but eh… there’s no penalty for bookmarking a site twice.

The integrated blog editing stuff is pretty nice, if lacking in some text-editing features right now, but that’s ok. Its a beta-level preview, so you can expect some rough edges, but its nice to have an integrated blog editor in your browser. I do like the way they’ve thought out the integration between blogs, Flickr and the browser. Posting volume should go up for those who use it.

Extensions are currently limited to what’s on Flock’s site, which is not much. I looked for the killer app of Firefox extensions, SessionSaver, and its not there. I won’t seriously consider using it until that one’s supported. (trying to install it anyway yields an error about how its not compatible with Flock)

The Feed Manager in Flock is different than FF’s Live Bookmarks (which definitely suck, so I’m glad someone’s tackling this). You subscribe to a page by adding it to your Favorites and then just go to either that page again or the Favorites manager to open the RSS feed. This opens a pretty plain page with the links and blurbs from the feed. I like this better than Live Bookmarks, but I’m not dumping NNW for that.

Overall, I’m glad to see so much development on Web browsers these days. They stagnated for years under the thumb of IE and now we’re seeing a resurgance in experimentation and development. Hopefully, someone will figure out how to integrate RSS into a browser with aa UI that makes you want to use it and we’ll all be happy :-P