I've been playing with some of the new Facebook applications. I have to admit that some of these are very cool. It might not be as closed as I first thought, but the PUD metaphor still works. With these new capabilities a person can do almost everything they want without ever leaving Facebook.
This is going to kick some serious butt. First off, if you are Yahoo, and run a service like del.icio.us, this leaves you in a very difficult spot. Do you write a Facebook widget to allow FBers to get at you? How do you ignore all those users? There is already a Ma.gnolia extension in FB. Does this not put Ma.gnolia in the drivers seat? I'm thinking the balance of power has shifted dramatically: Facebook, The Mighty Pipe, Could Crush Yahoo.
This is going to play havoc with a many of the Web's established enterprises: Yahoo, Ebay, Craigslist... Add to the list all of those startups that were hoping to be your new homepage: Netvibes, Pageflakes, and even iGoogle--which is still in the start-up phase. I just don't see how they can counter what Facebook has to offer.