Note: this starts this friday at 12:01am Noon some time friday, see the link PST, not right now. It's also unclear if you are required to create an account from the iOS app or not. Guess it's an easy test in 14 hours :)
I'm not a box.net user, but after seeing that they are Giving iOS Users Insane Amounts of Free Storage (50G) I'll be heading over and getting an account.
This is a response to iCloud's 5G free storage, though I don't think that box.net understands that iCloud isn't simply a dropbox-like solution, but more about integration with apps. Still, 50G free storage is nice :)