So, if you don't have your device connected to the net, and you're downloading and buying apps the old fashioned way, through iTunes, how on earth do you update them?
This touches on my oft mentioned complaint about iTunes. The store component sucks. And the App store sucks most of all because it's just a simple category in the music store. There actually is no app store. It's like HMV or Tower or whomever selling software on CD racks mixed in with the music. Integration of anything other than locally-accessible music in iTunes is also the pits. That goes for videos, apps, remote music and even Apple's own devices.
I'd really love to see a brand new application created called "iStore" and yet another one for handling videos. iTunes really needs to focus on music, where it excels (compared to everything else out there).