Which is to expected. As a spell, it's just far too powerful since it literally does anything (can duplicate most other spells even from the cleric spell lists). Even as a ritual, it breaks too many potential plots (all of them).
My solution would be to make Wish rare. Incredibly rare. Like:
- Wishes are granted by powerful beings such as gods, demon lords, lords of Hell and high-ranking efreets. Even they don't have total control of the ability - it's usually contingent on them first "granting" a wish and then having to follow the letter of the wish, making them reluctant to grant it in the first place.
- Wish should never appear as a power or ritual.
- A Wish can be much more powerful than in earlier editions, due to it's rarity. Wishing for level 30 items, large tracts of land or equivalent sums of money isn't out of order. Raising the dead, curing diseases or transporting the party anywhere in the Planes is almost a waste of the Wish.
- Ironically, I also feel that the DM is more free to pervert a Wish, since the player didn't pay a spell slot and XP for it. The degree of perversion should depend on the source, of course - efreets and devils will mess with you.
Well, those are my thoughts on Wishing in 4E.