Wow, you really stuck it out with that Touch Pro 2, huh?
I upgraded from the Touch Pro2 when the EVO 4G came out then upgraded again when the EVO 3D came out... I think you will be completely happy either way you go (EVO 4G or EVO 3D) since you're coming from a slow WinMo device. That being said, the EVO 3D is a much better, faster device IMO and I'd never go back to the EVO 4G. 3D is just a bonus. If you plan to root and load up custom ROMs, then you'll be able to keep the EVO 4G up to date though.
I also recommend waiting another month to see if you might want to get the Epic 4G Touch (Sprint Galaxy S II). Then you can weigh all your options and make the best decision.