I don't believe the Mortgage Insurance falls off of an FHA loan anymore. Depending on how long you've had your loan, it may or may not, so call and ask. I had to refinance my loan into a conventional to get it to come off.
If you do plan to refinance and use as a rental, are you going to refinance for the current value and use the equity to pay for the down on the new house? If so, make sure the rent you can get from the rental will cover the new mortgage amount.