Im actually amazed at the rolling release process ubuntu and some others have switched too.
In ye olden days you had to download another disk and install over your O/S or you had to open your update manager and overwrite the config telling it to look in a different location from where it then overwrote all your packages and broke any programs that you had compiled. It seems now the update manager in ubuntu can upgrade your distrobution off the network a package at a time.