Well, not just Facebook. Social networks in general. For most people, existing social networks have hit a wall. They were fun while they were novel, but novelty only lasts so long. Once you've got your friends and you've done the pirates vs ninjas thing so many times, the only spaces that survive are the ones that let you continue to build your networks or do something useful like share your photos.
In terms of the use curve then… we’re on the down-slope. After the first few months of overuse and excitement loading every ridiculous app available, most of us now only use Social Networks for a quick buzz… like email used to be. To me Facebook is like the next Hotmail. Remember how it used to be so much fun sending and receiving social emails. How you used to sign in just in the hope there was a message? The problem is that email became useful and then email became work.
And I think we're seeing the same thing with Facebook. Everyone is trying to shoehorn use of out existing Social Networks, but the difference is that they are struggling because most of them explicitly weren’t designed to do that.
Existing networks however, have created norms, laid the foundations and paved the way for the next generation of networks… useful networks, hyperlocal networks, gated networks… and we’re seeing these already with sites like Celsias and UnltdWorld. However these are really designed to allow people to organise online to do stuff offline, and as such are still a way off being either true social networks or truly useful social networks.
Personally I think that the harder that a true social graph recreator like Facebook works to make itself useful, the less love it's going to get from it's core audience, because after past experience we've become more protective of our social environment and more suspicious of corporate attempts to appropriate it.
I guess what I'm leading to is that I think we're ready for a truly useful social network. One that explicitly sets out to be useful from the start, and functions as the useful extension of existing social networks rather than coming in as another new competitor. And yes, you guessed it... this is the underlying driver behind what the Urban Survival Project is trying to achieve, albeit with a core focus on people helping people.