This is how I wish princess Twilight will turn out...
In the opening episode of season 4 (an awesome 2 parter shown back to back of course) have some kind of crazy monster show up. Like a ridiculously over powered monster...
To face the new threat, the combined forces of the Elements of Harmony, Discord and Princess Twilight's powers are combined in one crazy fight.
At the end of the fight the monster is defeated, but at the cost of Twilight's Alicorn powers.
Then in a reasonable compromise Twilight goes back to normal and no longer completely destroys the social structure of the show, while still having amazing profits from the Twilight Princess merchandise, which really, was the only reason this happened in the first place...
Yeah, that would sell me on season 4...
Now, would they ever do that? Not a chance...