My newbie understanding is that there will be copyright issues with the name - you would have 2 prove u intended fair use of the name and were not buying it only 2 sell it or park it...i could b wrong, but it sounds about right....if u had the original name with no prior knowledge of the future movie....then it'd be alright i think....but 2 claim the 5th series of an already established franchise... I think ud lose any court challenges...
my 2 cents
They'd send u a letter asking for the domain back prior to a lawsuit or any real legal proceedings.