What are the requirements for the Mark VI helmet in Halo: Reach?

Well, now according to the Halo Wiki the Mark VI helmet costs 300,000 cR and is unlocked at Brigadier, which itself requires 1,400,000 total credits. I suppose next month we'll see if that's accurate.

From what I've read on various (modding) community sites the Mark VI helmet unlocks at the "Commander" rank, a rank past the current level cap of Lt. Colonel. This is purely speculation, but I'm guessing (based on the way the ranks have progressed so far) the next few ranks will be as follows:

Lt. Colonel

• Lt. Colonel Grade 1
• Lt. Colonel Grade 2
• Lt. Colonel Grade 3

Commander <---( Mark VI Helmet Unlocked )

• Commander Grade 1 (w/ Picture)
• Commander Grade 2 (w/ Picture)
• Commander Grade 3 (w/ Picture)

Colonel

• Colonel Grade 1
• Colonel Grade 2
• Colonel Grade 3

UPDATED - Based on the newest information supplied by Gary on his last post! Commander is actually the next rank past Lt. Colonel Grade 3... We'll have that Mark VI soon!