In a world of Intranet turf battles, the easy answer is… well, uh… IT, HR, Corp Communication, Marketing, and so on, but in this social world isn't it really the end user should own its destiny?
I reference an article from 2001 "Our intranet doesn't need an owner. It belongs to all of us -- and to none of us.
Fortunately, that freewheeling approach is picking up surprising support from managers, consultants, and intranet users." Amazing that 11 years later, we are still trying to move in that direction.
Social Business would dictate that it isn't owned by any department if the platform is governed and setup properly.
The personalization and needs of all should be surfaced in a way that it serves the user. Join in the poll. I've created a poll to see who you think owns the Intranet. I'll replace your results with this best guess.