Can I get the iPhone 5 I currently have the 4s and my warranty?

I have the 4s and I still have my warranty I've been needing to take it in for the power button to be repaird will they exchange it for the iPhone 5 and ill just pay the difference

No. They will give you the same model you have. You have to upgrade to the 5 if you want it. They don't give them out.

Wait for the 5S

No, they will either repair your phone or give you another 4S. If you are already out of contract, they might offer you an upgrade to a 5, but you will have to sign up for another 2 years. The stores have plenty of iPhone 4S's in inventory to take care of warranty and repairs.