I had expected that all EOS DSLR users would be able to use the program, but also assumed there were some features that would only be available to "compatible body" users. Unfortunately, it looks like I was mistaken. DPP 4 will not open RAW files from incompatible bodies. So if you do not own one of Canon's current full-frame bodies, you're stuck using version 3.x instead.
From the viewpoint of someone who uses a 5D Mark III as a primary body and a 7D as a backup, I find this to be very inconvenient. It means that I have to keep two versions of DPP installed on my computer if I want to use the latest features while still being able to edit my backup body RAW files.
I hope Canon reconsiders this new software strategy. [Sean]
Download DPP 4.0 & EOS Utility 3.0*
* Please note: DPP 4.0 will be compatible only with 64-bit OS, such as Windows 7, 8 and 8.1, plus Mac OS X 10.8 and 10.9.