On a side note the 4s as it's being called is just a testbed phone, one that began as what would have potentially been a replacement for the iPhone 4 during antennagate. It led Apple to realize that the antenna as it was configured could not be "fixed" (my phone worked fine by the way with no more dropped calls than usual).
Not to mention that many sources have stated that Apple is testing iPhone 5 internals inside of iPhone 4 bodies so that the design is not compromised like we saw last year. My guess is that this is the origin of the "4s" theory.