TeamDrive 3.0 provides file sync, storage and sharing for enterprise – in the cloud or on a business's own servers – with encryption keeping the data safe. But it is quick to point out that it's not just DropBox for business. Dropbox and Box.net both offer file synchronisation and sharing services in the cloud: Dropbox for …
"If you host TeamDrive inside your firewall then your data is maintained on your servers under your control. You get file sync and sharing without having to use a cloud model."
That seems like a solution that might interest a number of companies for whom even relatively short outages would represent a serious problem.