http://blog.eu.playstation.com/
Honestly, the Playstation blog is fucking awesome! Developers talk about their games, answer user questions, and in general, it provides a very nice form of communication between the users and the developers. On top of that, it's a simple but effective tool for Sony to have, and I'm guessing it requires little management.
I know Microsoft have Major Nielsen's blog and Nintendo have just launched their Twitter thingy, but neither stacks up to the PS blog. So why not copy it? It should be one of the easiest things to do.