Phone Arena got some leaked documents on the HTC Touch Diamond and HTC Touch Pro for Sprint and Verizon, and it looks like Verizon's going to be slightly gimping their version of the Diamond. The general gist is the same with both having a 2.8-inch screen, EV-DO Rev. A, 3.2-megapixel autofocus camera, 802.11b/g, 1340mAh battery, internal GPS, and Bluetooth 2.0. What's different is in the processor and RAM.
Sprint has a Qualcomm 7501A processor running at 528MHz with a 32MB ISM, and Verizon has a Qualcomm 7500 running at 400MHz with a 54MB ISM. Slightly faster, but less RAM internally for Sprint. On the memory side, both have 256MB ROM, but Sprint has a 256MB RAM as opposed to Verizon's 128MB. That's half the amount of RAM on Verizon. Expect slowness there. But you do get an SD expansion slot on Verizon.
On the Pro side, the relative processors and RAM are the same (Sprint gets 256MB RAM while Verizon only has 128MB), but both have a 512MB ROM. Sprint's has a motion sensor on both phones while only having an SD expansion slot on the Touch Pro. From what Phone Arena's readers say, Sprint will have a 30 day exclusive head start on the two phones starting on or around September 2. [Phone Arena - Thanks Eric!]