I am not eligible for an upgrade until 06/2015. When I go to the Apple site and type in my number to check my upgrade eligibility it says I can upgrade now for $649.
So yes you will be able to pay full price tonight for a phone if you are still in contract and just want to get a new phone for that line. You won't be able to get a full priced unlocked phone though like you can now with the 5s