The software updates that you get now for 9.10 are largely security/stability updates. Unless you use ppas, you wouldn't be getting the latest version of a lot of software out there. The philosophy is to make sure you're always running a usable & stable system.

Usually, the different major versions of Ubuntu incorporates the updates to the major components including the Linux kernel, X.org, GNOME/KDE, OO, system libraries, etc. You also get the new Canonical updates thats targeted for Lucid, such as the new me menu.

I'm not sure if you knew, but JungleDisk just released version 3 of their software which lets you sync any folder in your computer. This is better than DropBox in that the synced folders can be located anywhere. I'm not sure how this works with the backed up files though, but I would imagine that synced files are also part of the backup vault.

Of course, this still requires you to upload the files Amazon or RackSpace. Just want to make sure that you are aware that you don't have to use DropBox if you're already using Jungle Disk :)