Samsung had it's day, and the last decent Samsung smartphone IMHO was the i700, circa 2004. Since then, build quality has declined, and the devices feel cheap. Hardware is no contest when comparing to the EVO LTE. Cell signal will be superior due to the processor, the camera will be unbelievable, and the audio system will be unparalleled in the Android world.
The Galaxy Nexus is already old news, outdated, and halfway through it's life cycle.
I'll take the superior hardware of the HTC any day, as I know there will be Dev support, and if you must have AOSP, you know that will be on the way, with it only being a matter of time. The original EVO was first rooted 2 weeks prior to it's release, so I have no doubts the same will be true for the LTE.
Overall, the HTC is just a vastly superior phone.