Meh, let's all be clear about one thing- anytime a change in a game requires whatever is being changed to be banned from official tournaments, then the change fails. No change should automatically require a ban as a result of the change.
That said, I can think of two soft changes that would make using cloak a little more useful without dramatic bannings.
1. Make it so all creature under cloak take less damage from global spells, such as lightning storm. Perhaps drop it by 1 or 2 damage?
2. When Cloak is stolen, set it so the counters stay the same at the time it was stolen rather than reset after being stolen. It's a benefit to steal cloak for the person stealing.
As for the stealing part, I can see a separate argument being created as to whether or not stealing in this case is related to cloak or to steal itself.