If you embrace the Post-PC, you likely drop Dropbox and rely on iCloud - via @Gruber

This illustration explains iCloud at it bests!

Wired has a long post on Dropbox vs. iCloud. They are telling the interesting story on how Dropbox manage to break into OSX Finder, what Apple's own MobilMe wasn't able to. But the comparison of two is almost absent. And the huge shift of moving the data from the PC to the iCloud are barely mentioned.
Some iCloud features, other than storage, that are making it disruptive are:

• Lack of filesystem user interface
• Filesystem implementation of versioning reduce storage of different versions of same documents
• User experience enhancement of synching create strong incentives to people to use iCloud-prepared apps
• Backup of devices apps and data gives user a much more secure mobile life

The first feature is the most important. User who can manage to forget the filesystem will have huge advantages in the ability to absorve new Post-PC work styles and processes.

The features have reduced my need for storage from 1Tb to less than 200Gb!

My advice is to delete your Dropbox and trust your data to iCloud. It will only better and better in many years ahead! And as a bonus, your can change to MacBook Airs. That's quite a benefit!

Thanks to John Gruber in DaringFireball.net for linking to it.