OK, here's the next idea from my list of great (and not so great ) ideas.

Make lots of new islands - we all want that.
Make many of them small.
Make many of them have a deactivated teleport on them.
Make a new teleport activation skill that you can target at one of the deactivated island teleports, and remotely reopen it for a set time, allowing players to jump through.
After x minutes the teleport closes again.

Perhaps tie in with the ability to upgrade the teleports making them need a higher skill to reactive. I'm thinking along the lines of chest/lockpicking but where the island is the chest and the teleport is the lock.