He's just implying that the release is going to be big. Another tweet later revealed he is still expecting a second phone release in 2012....which he has said early 2012 before. He seems to be of the opinion that there will be a release on the 14th, then perhaps another phone in early 2012 (which sounds bogus to me).
If by "iPhone 5" you mean a handset identical to the iPhone 4 physically but dubbed the "iPhone 5" then you may be correct. If you are saying there will be a teardrop iPhone 5 I think you will be very disappointed...