A prequel showing Freddy before getting killed sounds great! I always thought that part of the story could have been more elaborate.
If they decide to do it, I hope Freddy shows more of his dark side (as in the New Nightmare or NOES 1) and not his "comediant" side.
Hm.. allow me to advertise myself, here's a piece of fan art I did of NOES, enjoy! (or not)
http://www.deviantart.com/view/27056046/