Last month Konami released the MGO demo to the Playstation Store. My guess is that they where attempting to get a some people to buy MGS 4 or even get them to buy MGO eventually. Even though that is probably the case, Komnami added something to people who register for MGO.
The “Welcome Rookie” Campaign automatically adds 5000 points to the account, which can be used to buy items within the game. As an added plus the users also get the MGO codec pack, which gives players more voice commands. December 24, 2008 to February 16, 2009 is the time frame Konami is giving to new players to register and get these offers.
I see this from two perspectives. The first one is that Konami is giving a huge middle finger and a challenge to vetern players. The second is offering newbies a chance to stand up against the veterns. If the vetern players had waited a little bit, they too could of had this bonus.