Processor: it's only 0.3 GHz faster, but GHz aren't everything. From the benchmarks coming out it looks like the Evo LTE processor will blow the Evo 3D processor out of the water
Camera: again, blows the Evo 3D out of the water, but no 3D if you care.
Screen: This sounds like the best screen ever created for a smartphone. (More water blowing) again, no 3D if that matters to you
4G: WiMax is dead. I don't know if you have WiMax in your area, but I don't. No one has Sprint LTE yet, but Sprint claims that it will be rolled out quickly and agressively. So I'm hoping to get it in New Orleans eventually. If you're in a decent sized city, you should get it too ... eventually
Beats Audio: supposedly better sound quality if you have or purchase a decent set of headphones... meh
Storage: It has a lot more storage than the 3D and still has an SD card slot
Battery: It's definitly a bigger battery, but it's not removable
Kickstand: Woot!
OS: Sense 4.0 vs Sense 3.6 (after ICS upgrade). I don't what the differences are (and I'm keen to find out), but I'm just pointing out that we won't be running the same version of ICS as them.