Mystery grenade revealed

Today IGN broke the story about the forth grenade type and also confirmed something everyone hoped would be true...

The Flamethrower joins the party!
After being teased time and time again, first in Halo 1 and then in Halo 2, the flamethrower is now officially confirmed. It's considered a "turret" weapon and as such will force the camera into third person, slowing down whoever uses it considerably. The flames spit out from this monster will stick to anything (Including the bubble shield) and burn away whatever it touches. Flame walls can be used to keep out unwanted visitors from your base. The only weaknesses are that it can only be used in 3 second bursts and is very hard to aim with.

The Firebomb
The forth grenade type is like a mini flamethrower covering everything in flames when it explodes. This is a better option if you want to create a flame wall. Like the flare, when a firebomb goes off a bright blinding light is emitted. With so many different grenade types I wonder if the maximum number of grenades allowed to be held at one time will decrease.