The way I use the cloud storage services the account vanishing shouldn't hurt, because it stores copies on each of my machines. I use in more like a synced folder, than cloud storage.
(other than when I'm at some other computer accessing the account online.)
Now if they would delete my files and it ordered the app to empty the local folders... yikes.
Inactivity isn't likely either, I turn on one of my machines that's been off for a day, and it has to sync 200 files.
What we need is Dropbox to get nervous, and up their space.