Metal Gear Solid: Ground Zeros

Seems like the odd numbered Metal Gear Solid games are the better ones Metal Gear Solid, MGS 3 and now Metal Gear Solid Ground Zeros (tech demo for MGS 5 on the Fox engine) are the ones that really have amazing stories and push the limits of the system they're on.
So MGS4 gave us old Solid Snake and Ground Zeros shows the return of Naked Snake aka Big Boss but a bit older.
Technically the visuals are stunning, the sound effects sound amazing with so many levels going on at once the rain, the wind, the footsteps in the mud, the jeeps idling in the distance the hounds barking....this is what surround sound is for and all that will draw the player further into the games experience.
I'm curious about our crispy friend with the brimmed hat....for those in the know we all know how the original Metal Gear ended...are we actually seeing the end of MGS5?! And the boy in the cage....is that Jack/Raiden? It fits the time line....
Chico and Pax, who are they? Are they the two phantoms born from Fox?
This trailer has reignited my interest in the Metal Gear Saga and I can't wait to hear more about Ground Zeros, Big Boss, Cypher, Pax and Chico! Meanwhile I'm playing MGS4 again and going for the Platinum Trophy. I've also DL'd the MG HD collection and will be replaying MGS 2 and MGS3 for the trophies also.