Gamers who spend 35-75 hours will receive 100 MS points for free and those who play 70-140 hours will earn 300 free MS points for their game play. If you are addicted to Halo 4's multiplayer mode, you can receive 600 MS points for playing 140 plus hours of multiplayer mode.
Also, spending 1500 MS points on Halo content earns you 100 MS points, and spending 3000 MS points on Halo content earns you 200 points. However you can only earn them by the end of November, and can only earn 800 MS points altogether.
I'd say it's barely worth it, but that's my opinion.
Halo 4 will not be making it's way to the personal computer. Just like it's 4 predecessors, Halo 3, ODST, Reach, and Wars, it will remain a console exclusive for the Xbox 360.
The following information is courtesy of *Nocti-Vagus
The eggheads of the Halo community are working together to solve the secrets of the Section 3 Archives on Halo Waypoint.
The following codes will allow you to unlock exclusive Halo 4 content and credits, via the Classified section on Waypoint: [link]
The known codes so far: [link]
WISEGUY code: [link]
Section 3 Archive - ONI code: T 5 C E 6 K V 3 R 8
Section 3 Archive - Wiseguy code: Q W E 6 2 1 K N 8 F
2-Dot code: _ C _ V _ Q
Requiem Archive 1 code1: 1 U K 3 C V Y J Z M
Requiem Archive 1 code2: 3 V G R Z J 1 B S 6
Requiem Archive 1 code3: Q 2 3 9 S F 2 P G Z
If you wish to thank or help these geniuses out go here and read up:
You must find and watch all 7 of the Halo 4 campaign terminals before unlocking this extra content, so here's a terminal location guide video below: