I believe that there should be some packages in ubuntu that **should** be protected, meaning that the user will have to comfirm the removal, after reading its possible effects.
This can probably stop the amount of people from removing network-manager &like
1. Synaptic/Software Center should emit warnings to users if they attempt to remove a package that could possibly cripple their system, along with the possible effects of removing it. This warning can be turned off through the editing of synaptic settings or from a config file if the user doesn't find them useful.
2. Cache Network-Manager/Other important apps in the apt-archives as part of the postrm script
A lot of users want to try another networking manager such as Wicd to see if it would fix their networking problems. However, if it doesn't, and they are left with no internet, they will have to manually copy over network-manager on to the computer. This is highly non-user friendly behaviour. If network-manager is in the apt-cache, reinstalling it should be a breeze. The network-manager takes up less than 1mb here, so there shouldn't be problems regarding space
3. Synaptic/Software Center should have a "undo changes" option.
I have seen a lot of users simply click "ok" even though they were unintentionally removing tons of packages. In the end, they would have to look through the logs for the packages, which is also highly user-unfriendly behaviour. The "undo changes" button would allow users to undo changes "a step at a time", without jumping around, in order to prevent them from making a bigger mess. This also allows users to remove packages that may have fried their system without them needing to remember the packagename
All of this may seem like a long haulover, but it is better for newcomers to Linux (Most of this stuff won't affect experienced users anyway because of the option to turn these warnings off)
Vote Here -> http://brainstorm.ubuntu.com/idea/25328/