It's funny because the origins of Ubuntu One were a clear attempt at getting some SAAS money. Finding revenue streams has always been an issue for Linux distributions, especially consumer-oriented ones like Ubuntu, and UbuntuOne was yet another stab at the problem. Then they found that it's hard to compete in SAAS against giants like Microsoft and Google, where that sort of service is often a commodity driving profits in other areas. Focused companies like Dropbox can do it, but if your focus is elsewhere, then you don't have a chance.
Canonical does seem to have more trouble finding reliable revenue streams. This is probably due to their focus on more end-user-oriented support and features. Among the Linux distro 'major players', though, they're kind of the odd ones out. RedHat and SUSE have been doing pretty well for themselves.
RedHat and SuSe are both oriented towards enterprise server (RH) or enterprise desktop (SuSe): large-scale deployments with big support contracts.
Ubuntu has gone for consumers (home users, home servers), where nobody else ever managed to build a profitable and sustainable business in the Linux world.
I wonder what they'll try next.