Take a look:

all of the games are being rebooted into ps3, handheld, and cloud.

Hideo Kojima is using this as a way to milk the old games for money on a new project.

What the hell is this weirdo up to?

ZOE 3 finale?
New game?
New engine?

Damn it kojima, what are you trying to do?
TELL US!

I think it's pretty obvious the guy's testing the waters to see if it's worth it to make a fully fledged sequel. I mean, Revoltech figures, HD Collection, 3DS game teaser... it adds up.

The whole 3DS tease kinda worries me, I realise the 3DS is basically a scaled down Gamecube in terms of processing power but I've yet to see anything on the system that really pushes it to it's limits. Compare say....Metroid Prime to Zelda: OOT 3ds. There's a largish difference in graphical fidelity, and the size limitations on the 3DS carts could be a problem for bigger games.

All in all...I just hope that tease was a follow on or remake of Fist of Mars, that way we don't have to compromise on ZOE3.

@Raziel
I wouldn't worry myself over the 3DS release. It'll most likely be a remake or sequel of FoM or even a spin-off which will introduce some characters or concepts for the third game.

Well...we know that he's working on a new engine. The Fox Engine was announced at E3. As for ZoE3, I figured that if the collection sells well and makes a lot of money, then he would make it

Do you think ZOE 3 might be made on the Fox engine later on?

Yea, I do. I don't think we would announce it if all of his games weren't going to be on it. I don't know how long it takes to create an engine, so if he announces ZOE3 before this is done I guess it would be on an older engine. But my guess is that when it comes, it'll be on the Fox Engine.

heck yeah i want to slash enemies in slow motion/bullet time
whatever style (in zone of the enders)

Call me out if I'm wrong but wasn't the 'Fox Engine' being developed as the rendering engine for "a previously unannounced game" that most people assumed was MG5? (Note: not MGS5)

Initially I thought MGR would be using the Fox Engine but I believe they said MGR was being built on an updated version of MGS4's engine and using a new render engine that performed better multi-platform. Since the Cell Processor has a wildly different API to standard architecture processors (ie: the 360 and PC's) that made sense.

All that being said though...I can't remember where I heard the MGR news so take it with a grain of salt.

Edit: Just an FYI, we throw around the word "engine" a lot in most gaming forums but the definition of an engine in software engineering is basically the core set of functions/sub-routines that are called to directly (or indirectly in the case of higher-order functions) to make 'something' happen. This can be as simple as the sub-routines that display messages in the command line interface or as complex as a high-end rendering or physics engine. The amount of time it takes to build one is hugely variable based on the size of the project, the number of engineers you have and their individual experience. So it's not really something you can predict without a LOT of information we don't have.

Do you remember when Kojima was tweeting about that taboo game? I assumed that it was going to be a project using the Fox Engine, but I don't remember clearly. I don't think I read about Metal Gear 5, is there any sort of link on that? I do remember that the impression Kojima gave me was that the Fox Engine was going to be a Kojima Productions standard, all future KP tittles would be on it. And I think you are correct about Rising using an updated version of Metal Gear Solid 4's engine. I do remember reading that, but do you think it's possible that updating the Metal Gear Solid 4 engine has evolved into what we know as the Fox Engine?