i think what people tend to forget is that the uncharted franchise was shown to be undertracked by vgc. Uncharted shipped 17.3 million as of april 2012. while VGC had it at around 14m~ sold by the time. we know the PSV version didnt do much. we know at that time that uncharted 2 was spot on with its tracking since they announced it sold 4.9 million   and at the time VGC showed it at 4.8 million. so it leaves two games where the under tracking happened. UC1 and UC3. considering that UC3 shipped 3.8 first day, and it was recently released when sony announced the 17.3m number, realistically it was the game that was undertracked. its not out of the question that UC3 is 1.5m, 2m or even more undertracked. 

Considering how the PS4 is doing, and how Naughty Dog is one of the most loved studio in gaming history (ONE of them), it's possible.

Uncharted 4, while remaining true to the series roots, also seems to be somewhat darker, more mature in its tone. It was already the case for UC3 (which got way more personal with Drake). So the TLOU fans will probably give it a shot. Add to that the hardcore Sony/Uncharted fans and all the newcomers, and 10M is far from impossible.

I think it won't go over 9M, which would already be quite amazing, but it's a possibility.

5.9 million

10m is a bit hard, 8-9m seems more possible.

That's so not true 

3 million early on, 7 million tops.

Uncharted has always been one of the most bundled games and never hit 10 million. Tlou might be the most bundled game ever and never hit 10 million. Uncharted will be no different, 7-8 million max.

If it's bundled then maybe. I'm jumping on the 7-8 million bandwagon though.

So what does that have to do with anything though? ANd your second sentence is just COMPLETELY false and nowhere near true and I am prettys ure you know that as well.

Why do you say 7-8 max when UC3 is already approaching 7mil? And TLOU is only what 2 freaking years old and it is still selling as well.

Anyway OT I think it will easily sell7-8 mil and might fall JUST short of 10 but sell over 9 so I will say somewhere between 9.1-9.5mil.

Sorry but you seem to have some serious misconceptions. Once Uncharted 4 is released the PS4 will have sold ~30-35 million units and that number will grow by an additional ~15-20 million in the following year. The size of the PS4's userbase will in no way restrict the popularity of Uncharted 4. Gran Turismo 3 outsold GT4 and the PS2's userbase was tiny compared to when GT4 launched. Additionally, I must take issue with your statement that you based your prediction off of Uncharted's history because this is clearly not the case. If you did use the sales data of the past titles you would arrive at the conclusion that Uncharted 3 will sell at least 7 million units, not significantly less. Sorry but 4 million is not even a remote possilibility unless Uncharted 4 is a huge critical failure.