Do you think the rules for forced movement require revision?
Currently, sliding does not provoke AoOs, and it apparently disregards terrain. So in theory, a PC could use a power like command to order another PC to slide a certain distance, which among other things, could allow him to escape immobilizing effects such as being grabbed, and he can still move away to safety (since being slided does not provoke AoOs).
Those limitations were clearly instituted to prevent monsters from being at the mercy of players (such as pushing an enemy past multiple PCs having it provoke AoOs from all of them), but the flip side is that it then becomes some sort of "get out of jail free" card because it allows you to bypass just about every sort of restriction on movement.
Thoughts?