Provide funcionality to go back to a former system state

In history window, on the left there is a timeline of when you did changes to your system, on the right, there the changes are listed done at that specific time. The idea would be to provide two buttons below the list of changes.
One button that says "Revert ALL changes done since this time", which reverts system state to the state at this time. This would be good if the system stops to work properly.
Another button that says "Revert changes in THIS list" (if it is possible), which only reverts these changes displayed if possible. This would be good if you installed a program and don't really need it or something, and so delete it and all of its dependencies.
I think this sould be no real problem to implement, as full history is kept in Synaptic. The only problem I can think of is that changes made to the system state with apt and dpkg on the command line are NOT in Synaptic's history.