I’m always curious about how application uninstallation works.
By way of comparison, the Palm never had a proper uninstaller.
I’m surprised I’m saying something good about the phone I’m supposed to buy tomorrow, but this is well thought out.
… If you delete an Application from your iTunes library, the next time you sync your iPhone or iPod touch with that computer it will be removed from the device. If you delete an application from your device, but not from your iTunes library, it will be synced back to your device the next time your connect to iTunes.
If you normally sync applications to your device from one computer and then connect it to iTunes on another computer, iTunes will not attempt to sync applications from that library. Applications can only be synced from one iTunes library. If you are connected your iPhone or iPod touch to an iTunes library that you don't normally sync with, you can still transfer purchased applications from the device by choosing File > Transfer Purchases in iTunes.
It’s an extension of how music is managed on the iPod.