When? I've only heard them state that they're aiming for 60FPS. 

http://www.gamespot.com/articles/the-last-of-us-remastered-devs-discuss-making-60fp/1100-6421147/

"But being able to compare apples to apples like we have now with The Last of Us, going back and playing the 30 Hz version feels, to quote some people in the office, 'broken.'"

True, but they did give the option at 30FPS anyway lol.

It sucks that some people care about things I can't see more than things I can.

I do not feel any difference between 30 fps or 60 fps.
It won't be a problem for me.

If the PS4 and Xbone can't handle 1080p60, theres a big problem imo. My three year old gaming PC cost me 700 and still handles 1080p60 on medium... if the systems can't handle it then they shouldn't have been released yet. 4k TV's are becoming more affordable and within 5 years will be in finacial reach of most of the middle class. Meaning that 1080/60 is something that shouldn't even be a question with this generation, it should be the standard.

It seems to be a problem with western devs. This will sound cliche but their obsession with graphics is strange and destructive. Ground Zeroes proves that a game can be open world, look good and still run at 60fps. I dont understand their logic, would Uncharted 4 look that much worse if they targetted 60fps? Would it really.

Experience means the whole package.
FPS is a part of that, but my no means the most important thing as far as gameplay is concerned. For a game like Uncharted, particularly this one the level of damage or I should say accuracy and precision of it seems to be on another level.

Right now the game has that, with probably other things that haven't been shown yet at 1920X1080 30FPS locked. Being that the game's code is already running this way in pre-alpha, which is highly unoptimized compared to where it will be by launch things can only get better.

I doubt any sacrifices will be needed to achieve a locked 60FPS, but if Naughty Dog can add a lot more in the way of gameplay features that demand that extra headroom, like some huge avalanche in a snowy area, a truly volumetric sandstorm in a huge open environment or a volcano erupting all over the island then I can see where they're coming from, ND should have to limit the impact of those things to achieve 60FPS.
There's plenty of other things that can impact the players experience without talking about graphics and IMO those things could be far important to the game's experience than having a feature that doesn't give the game it's own unique identity like having those huge impact events in the game. 60FPS is IMO great, but the things you may have to sacrifice to have it may just not justify the costs.

Maybe Uncharted 4 can achieve all of those things I mentioned at 60FPS, I don't personally see why not, especially when you consider that we're months away from release, the state of the game's code the last time we saw it running in real time on PS4 and the fact that developers have only had SDK 2.0 for around a month or so prior to the demo being shown at PSX.

The ICE Team will no doubt be refining multi-core support for not only physics, but AI and all other general features of the hardware. Uncharted 4 will probably be the 1st game released to show all of that off and 1080p 60FPS will be a lot easier to achieve with all of that in place.

We'll see what happens, but people are jumping to conclusions that 60FPS automatically can't happen because ND says they don't want to compromise in other, important features to the game in order to be able to slap the 60FPS badge on their game.

It's Naughty Dog's game, they should be able to make it whatever they want if they feel it's what they want, if people don't like it then they don't have to buy it and Naughty Dog's development team knows that!