I recently toured two data-center's of a very large social networking site
MySpace? =)
(under NDA) and they are moving most their architecture away
from NetApp and toward 3par. They are however all FCP due to being a web facing shop who uses almost exclusive Windows, so once again it depends on the architecture.
The problem with the MySpace approach is that it is guaranteed to be far more expensive than a similar ONTAP setup (A multinode GX system.), not the kind of infrastructure model to adopt if you're looking to *cut* costs.
Regards, Max