I just read about an article about a "Cloud of real time information for London 2010". I wrote a bit in my blog in Spanish, there is an automatic translation here.
I won't write too much about it, I would prefer to you to go to the Cloud website or to the original article from TechCrunch or in . However, I would say that the project seems quite a challenge and I am looking forward to hearing more about it in the near future.