Interesting, as I have a bunch of older EA/Origin games.If you still have the CD with the serial # then you can actually contact EA and they should give you a new copy via Origin. This holds true for all their older games IIRC. I guess now it doesn't matter since the game is free but if you have older EA games with keys that are now on Origin definitely contact them. As bad as EA is perceived to be, their Origin support is actually pretty giving and nice.
How exactly do the new copies differ from the old? Changed code to support newer operating systems?