hadoop in a word. Very involved in the development of the hadopp file system and I guess it's going to be their googlefs equivalent for content hosting.
I'm also guessing that flickr will be in the [does | will do] box as well.
Which is kind of interesting. And leveraging off opensource save some of your development costs as well.
And as a bit of non sequiter (ok I want to keep track of the url), there's an interesting tale from the NYT about hadoop, Amazon's cloud computing environment adn digital content management