A new, CDMA version of the iPhone which is set to appear on Verizon Wireless may well be in the pipeline if the guys from BoyGeniusReport are to be believed.
One source has toldBGR that the iPhone version 3,2 is in AP testing stage which is the last step before being released to the general public.
It is likely that the new iPhone will be a CDMA + GSM model that will supersede the current model and will include a few improvements on the iPhone 4 MK1, the most notable being the antenna design.
Don't expect Apple to release the new phone as an iPhone 4.5 or even to acknowledge that it is indeed an upgrade/better model.
BGR also says that the next generation iPhone 5 is in the EVT (Engineering Verification Stage) chamber after which it will be passed on to the DVT (Device Verification Stage) team.
Interestingly, the infamous iPhone 4 which was lost in a bar and which "emerged" later on Gizmodo was a DVT model which means that Apple has almost finished designing the iPhone 5.
The next iPhone 5 is likely to be launched in June as it is usually the case and we expect it to keep the same hardware configuration.