Some rather inquisitive guy found something rather interesting in the source code of the official page of Made to Game. (Thankyou for the tip Jo!) The page which simply shows the invite contains a hidden message, presumably from the developer who made the page. At the time of writing the message is still present in the code and can be viewed using a debugger on this page.
Nvidia to launch a 'new gaming platform' at 'Made to Game' - probably an Android Console
The invitation was sent out some time back and simply stated to "join me [Jen-Hsun] for a very special evening on 3rd March". It also throws around words like redefine the future of gaming. People were most definitely expecting a Tegra X1 SHIELD product but I doubt many were expecting an Android Console. Which seems to be just as likely now. If you press F12 on the page and then navigate the code you will come upon the following message:
On March 3, you are invited to join NVIDIA CEO Jensen as we unveil a revolutionary new gaming platform.
So its a revolutionary, new, gaming, platform. Okay. What exactly does that mean. Well, if you combine this particular revelation with the fact that Nvidia has been hinting and hiring developers in the android console development program the chances of it being a mini Android Console go up exponentially. The fact that Nvidia has been working on it for "5 years" also starts to make a teeny tiny bit more sense (as opposed to a new iteration of SHIELD).
Needless to say such a device will almost certainly be powered by the Tegra X1 SoC. With an insanely powerful 20nm chip in the heart of their system, this console could actually pose a significant threat to current competitors the like of Ouya. Since Tegra X1 SoC would support (and actually have the horsepower) to run advanced features such as the full desktop renderer of Unreal Engine 4 and AEP (Android Extension Pack) the visual acuity of the platform would be unrivaled as well. It also goes without saying that I could be wrong about this and Nvidia is either 1) launching something brand new and never seen before that actually goes on to redefine gaming or 2) this is just glorified marketing for the new SHIELD iteration.