Halo 4 - Possible new enemy info

We have seen the last part of the trailer put together (If you havent here it is:)

So, we can see here that our "new enemy" is a biped, has "alien" arms and has a red laser in the shoulder. That red laser is like the one from the spartan laser, but, as you can see in this image:

There are three lasers in this pic, so what other weapon or thing can make this awesome red laser, well, only one, the one you all hate from Halo 3. The Guardian Sentinel.
The Guardian Sentinel is a special sentinel designed to protect or limit areas to other living beings, his red eye whas a powerfull laser that could be used as a weapon if he was killed. The Guardian Sentinel was originally set to appear as a fighting enemy in a campaign level that later became a multiplayer level Guardian but was removed, and featured in The Art of Halo 3.

So it maybe means that this is a Guardian Sentinel, or someone using him as a weapon. By the way he stands and the shape of his arms, i personnaly think it is the Arbiter. But, if you look closely, you'll notice that the arms are not holding the weapon, but, Precursors had four arms, this could mean that the image is from a precursor holding a Guardian Sentinel or another weapon with his upper hands. Thats all for today, post your comments about what you think about it.

Halo 4 - Forerunner book image has reference to Halo 4 Concept Art Trailer

Hello there, i found out that this image from the book Halo: Primordium from the Forerunner saga:

Is the same that this one from 343 Industries concept art trailer:

This means many things, first, Halos will appear in Halo 4, at least what looks like a small halo at the right of the both images. Also, maybe this book has to do something with the Halo 4 plot.

Halo 4 - The new enemy

Finally, i've managed to edit the final scene in Photoshop, and it looks like this:

First edition, it doesnt look good, let's Photoshop it:

Now, let's edit it to make it look better:

So that's the new enemy, post your comments about what it could be, personally i think it might be the Arbiter.