Sony PlayStation chose not to reveal the PS4 Neo at E3 2016, possibly because Microsoft was showing off the new Xbox and they didn't want to get close to that foolishness.
There's still a rumour that PS's new box could arrive this year, and this new leak suggests that the specs at least are fully locked in. The info comes from what looks like marketing materials for the PS4 Neo and you can read them all over here.
One big point that is repeated is that the current PS4 and Neo will be on the market at the same time, and it's important to make it clear that all of those games will be available for both. It's a way of making your games look better, especially on 4K TVs, and you'll get nicer graphics on the new box.
In terms of the specs, its a pretty familiar lineup:
CPU: Uses same “Jaguar” cores as the original PlayStation4, at higher frequency – Original PS4: 8 cores at 1.6 GHz –NEO:8 cores at 2.1 GHz (1.3x faster)
GPU: Uses improved version of AMD GCN CUs, more CUs/at higherfrequency
Memory: Uses same 8 GB GDDR5 as the original PlayStation 4, at higher bandwidth
HDD: Same as original PlayStation 4
Really this is a very similar machine that has been boosted to be able to handle better graphics, like putting a new card into a PC. That's been done for a few reasons, but mainly so that the Neo versions of the games don't have to be recoded for different architecture.
There's a roadmap in the document which talks about early test models being rolled out and returned to Sony, all ending in March 2017 - could that be when the new system will launch? Time will tell, but the launch is obviously fast approaching.