Technology and the speed it moves is unpredictable at best.

No one out there speculating on the internet can give you an accurate answer to your question.

All you can do is make an informed decision. Does the current iPhone do everything you want it to do? If so enjoy it now.

If you know of a hardware feature that's must for you that the 4s doesn't have and that'll ruin your experience if you don't have it then return the 4s and sit back with a.n.other phone until the 5 comes out and hope it has that killer feature.

In real terms an iPhone 5 is very unlikely to make your 4s look stone age. It's not what has happened in the iPhone lifecycle this far. Sure, it may look different, have a faster processor, different size screen maybe, NFC, microwave oven and molecular teleport but if you're happy with your 4s now I wouldn't worry