I believe each and every single of such websites or systems makes the world a better place. Everyone has a slightly different system, so in the long run some will survive and change the world, some will not.
A few days ago I noticed a new one and immediately felt that I wanted to participate. I had previously tried another one, but could not get enough visibility, as there was thousands of projects and the website did not show random projects to users, so it is up to you to attract enough people to support your project. From the natural traffic of the website I could get only less than 10 people to see my project, let alone support it. I guess one needs thousands of people to see your project so that a fraction of that will decide to support.
As I noticed that the new one has few projects at the moment, posting a new project will be visible to everyone that checks the website. (By the way the url is http://www.rockthepost.com). So I did post a project. People that visit the website get to see my project, however as the website is new there are few visitors . The website is around one month old I guess. So I hope that in the duration of my project (60 days) the traffic will increase and I will get enough support.
I would recommend anyone with a suitable project to try this website as it is still young and you will get free visibility. I guess visibility is the most valuable thing on the net novadays. Thinking in terms of Seth Godin’s permission marketing, everyone that checks the website is coming with their own will and permission. You cannot get that kind of attention with advertisement etc. If the website can be successful, it will be full of projects and once again we will need to struggle for visibility. Then we will need to catch the new train I guess.