When coming up with the design someone clearly looked back at Arthas. I’m even wondering how many echos of Arthas will happen in the upcoming xpack. It’s really to early to say, but I wouldn’t doubt a quest line or something were Anduin is confronted with being Arthas. Look at the main characters of the xpac among them are the Arthas look a like and Sylvanas. My personal hope is a showdown between Jaina and Illidan, but I’m not holding my breath for that. Still when WOD came out I remember thinking they were heading towards another Lich King, but I’m wondering now if it will be something worse. There will always be another villian ready to take over Azeroth, but I don’t beloved it will be our beloved Prince. Right now it seems his character is heading for a ‘I’m going to be the man/Prince/King Arthas couldn’t be.’