Remove the following things:
All ability to teleport to Dungeons, Make everyone ride there.
Remove Flying mounts from Azeroth
Remove all high level guards from low level towns and villages
Buff Dungeons so that you actually need to play your class properly
Remove at least 50% of wind riders and graveyards, get the traffic back on the roads
Remove Ability to teleport into Battlegrounds, make us go to battlemasters as in the old days (just make more of them to avoid griefers).
Remove a lot of phasing as it ruins immersion when you chase someone and they suddenly vanish.
Add the following things
All future expansions should take place in Azeroth, do not add any more zones, just develop the story on Azeroth so it thrives once again.
Conclusion
Ofc none of this will happen as the tears that would be shed could possibly flood the world and wipe us all out. The new breed of player has no balls, has no ability to shake him/herself down after being ganked and certainly has no patience to ride from A to B. Can you imagine the wow players of today trying to survive in Vanilla, they would have a heart attack at how hardcore it used to be. No I am afraid MMO's now are so easy, so spoon fed that the players today simply could not cope with old wow.
From a business point of view Blizzard are currently their own worst enemy, they are killing the game by making it so easy and forgiving. If they opened a BC server millions would return, but this would be an admission of doing it wrong and the PR department won't allow that