Of course I am not a lawyer and don't have any extensive knowlege in this area, so that said, I agree with you. I feel it is a little more honest to admit this design is identical to the Long-EZ and for discussions sake I will call it that.
As to registering it I agree that it would probably be officially a different name. If I were to purchase a second hand set of plans I might consider using the Long-EZ name to register it, but without a SN this seems to really get down to symantics.
On another note, when should I contact the FAA and let them know that I am building an aircraft? I remember reading that there would be required inspections during the build, but also I read that that has changed and the inspection is only before testing.