I read this article over at AllAboutSymbian some time ago. It seems 3 want their users to create their new portal, web 2.0-stylee. In a corporate context, this might sound like a superb idea: someone else does the work, you cash in. It's like with open source around 2000: there was a wide-spread perception that you could just upload your code to sourceforge, and thousands of nerds around the world would start doing the work for you, Linux-style, or Mozilla-style. However, those nerds need some sort of incentive. It just won't work for any project. It works exceptionally well for cool projects like the Linux kernel, but might not work as well for something completely uncool, like an office suite.
Web sites with user contributed content work great if the users feel that it's a good service, ie. if it's fun or useful. Adding links to mobile sites to 3's mobile portal probably isn't much fun. I know I couldn't be bothered.