I've been an enthusiastic convert to Cloud living since I discovered Gears, the Google extension that allows me to take web apps (Google Docs mainly) offline with me.
It creates a local database that backs up your Docs data and synchs it with the online version as soon as you connect back to the 'Net. The interface for Docs suits the way I like to think more than the now clunky, hand-me-down files and folders concept of Word and its ilk, and being able to carry it around and switch between my works PC and my two home machines without needing to copy files back and forth actually helps me a lot.
With this kind of platform neutral feature adding real strength to the 'the-browser-is-the-OS' argument, you could be sure that the boys in Seattle weren't going to let their stranglehold on the desktop/office slip away too easily.
The response is Mesh, a kind of synchronised folder for the net generation. It requires that you install Mesh on each machine and as far as I can tell, still relies on nominated 'meshed' folders, but the basic principle is the same - work on one machine and the files will be available on any others just as soon as Mesh can check back in with the mothership (ahem, connect back to the 'Net).
Since this will still, as far as I can see, perpetuate the files and folders system, I am unlikely to feel the need to opt for this in a personal capacity, but if it means flexible working without lugging the laptop for example, then I can see clear benefits.
The real star of this post is actually the 2008 Learning Trends collaborative tools mindmap, but then I like to hide the subject of my posts down here at the bottom as a special treat for those of you that read this far.