Plans to instigation of the fight between NCR and Ceaser's Legion. Like the shooter supplied both sides with weapons and is make butt-loads of caps from it.

Or the Ray Sphere from InFAMOUS

wtf dude you totaly stole the plot of far cry 2. i think plans to destroy the NCR and ceasars legion so that Mr house will become a King, but the real plan here is so that the man who hired you can lead a rebellion to start his own government of new vegas, a devios plan that could only be led back to you, but the trick is he also shot you, knowing that you planned to tell Mr House in a grab for a better life at the lucky 38, he stole the message and had to find a dummer courier than you to take the plans to his informat in the city, he thought you were dead, but now your all to alive, with no memory you hunt for answers.

its JFK'S LEFT HAND

The Package holds the last playboy left in exsistance

Well this all depends on who the shooter is and what faction he belongs to. Does he work for Mr. House at the Lucky 38 Casino doing shady work? Or was he an assassin working for N.C.R. or Ceasars Legion? Or he could of been a bandit or a slaver just out for some extra money, or a Merc with the same agenda. Either way, it would make a big difference as to 'What?' if we knew the 'Who?'.

From what I can understand so far the package is actually on its way to be delivered to Las Vegas, still the Sin Capital of the world and of the wastelands. So I think this kind of rules out Mr. House having a hand in it inless he's trying to cover something up. It seems to me that he is probably quiet the mob boss and would be fairly under handed with these types of things. Have someone else deliver the package halfway and have him shot down at gun point by a merc, and retrieve the package and take it to a secure location for pickup since you wouldn't want a merc coming to your casino to drop something off as that would kind of give it away. Anyone who knew about the package in this scenerio would have to investigate a great deal to find out where the package ended up even though it wound up safely in Mr. Houses hands. And I would say that in this scenerio it would have to be engineering plans and possibally information on military personel on Hoover Dam. He already runs Las Vegas yet he doesn't own the power grid, the N.C.R. controls that I believe. And what would make a powerful man more powerful? The ability to control the welfare of the people in his city at all times. Shut down the power or the water. "Let their be light and prosper" or "Suffer in the darkness".

Of course, we can also asertain that atleast two factions are vying for control: Ceasers Legion and the New California Republic. The two prodominant factions in the wastelands, so powerful that they have created their own monetary system. Legion Coin and N.C.R. Bucks. But now with lots of other factions popping up all over the wasteland they both have more competition. What easier way to snuff out said competition without much loss on your own side then to side with your biggest foes? The package could of contained a temporary Treaty of Peace that was on its way to Las Vegas from Ceasars Legion for pickup by an agent of the N.C.R. to be then delivered to the N.C.R. headquarters at hoover dam. But someone else had something else on their agenda. Take the package, keep the peace treaty out of the works and let the two biggest factions in your way tear each other apart and then they step in and clean up. Taking control of Hoover Dam, an infinate power source in the wastleand along with N.C.R.'s mint they have in possession and able to mint money that can be backed by both electricity and water; and taking control of the gold operations of the Legion.

a human head, probably your wife's. (movie reference.)

It'll be a briefcase. And we will only see an ominous, gold glow emitting from it when opened.