I'd buy the Halo season pass. Not because of the discount, but because I would just enjoy the feel of commitment to a new game of the multiplayer franchise I love and that has no equal. I've been paying Bungie Pro for years and I've barely used its perks.
And I'm watching the Multiplayer panel right now, and it's been really nice so far, much better than what you guys were making it sound yesterday. Can't wait for the Q&A lulztrain.
Oh, and the Halo 4 panel that I finally watched last night, GOT ME HYPED BIG TIME!!
edit- SHISHKA RETURN TO GAF YOU'RE AWESOME