To me, it's more the principle of the thing. Both Peter Jackson and Bungie have worked long and hard on their respective products, but if everyone only cheaps out and buys the regular version that means that 1) they'll make less money, and 2) they probably won't do something like that in the future. Personally, I have all three LotR movies in widescreen and the first two special collector's edition boxed sets. And yes, I have watched most of the extras. There are so many, in fact, that it's hard to even watch them in a single sitting, which is an awesome feeling. So yes, I preordered the Special edition, I mean really, it's only $5 more...
I went to gamestop to get a momory card (psone) well I preordered Halo2, the guy at the store was really honest. He mentioned the limited edition only has a special case (thats cost a whole 5 cents more) and the movie. As I can live without both I got the basic. Its like buying the special edition lord of the rings dvds are you really going to watch the extras that much?