Sure, but about 5 months after it's E3 debut.  They were shown in the Gameinformer november issue.  Unless there were some before that that I cannot remember. 

They had it in 2014 in the first place?

They're not gonna release 2 Third Person game within the same 3 month period during the first Holiday, that would be very counter productive. As soon as the Order 1886 got pushed to later in the year, it was a given that Uncharted would be a 2015 game.

And we haven't seen or heard ANYTHING about Uncharted besides that trailer with "UNCHARTED" in it.

Just in case anyone isn't aware, since it sounds like some people think Naughty Dog is a single team studio, they actually run with two full teams. The studio was split after Uncharted 2 with one team working on a sequel while the other team worked on a new IP that ended up being The Last of Us. The team that did Uncharted 3 has been working on the next game since shortly after they finished their last project. Unless you want to believe that the team which did Uncharted 3 took a vacation of one year or longer.

A Naughty Dog team has never taken longer than three and a half years to release a game after their last project. That game was The Last of Us which was a new IP that was started right after the studio split in two and it was delayed. It's not like this is a new IP. They've been working on this franchise for quite a few years now. It being on a new platform hardly matters considering who we're talking about. A studio that released a new IP on a new platform within two years of its last project for three generations in a row (Crash Bandicoot, Jak & Daxter, Uncharted).

So if you're wondering why anyone would believe that Uncharted 4 is coming within three years after the last Uncharted game and not even being bothered that The Last of Us launched last summer, that's why.

A third person view is the only thing Uncharted seems to have in common with The Order. I really don't think it's a big deal to release a Gears of War-esque third-person shooter within three months of a Tomb Raider-esque third-person action platformer. That would be like worrying that Skyrim was going to take sales away from Battlefield 3.

Yeah this^. A one and a bit year time to launch a game after announcement sounds quite short and atypical of sony. I would say its going to be an early 2015 release.

more time to polish it
this entry is very critical to the franchise imo, i want to see some major changes more balance MP, make drake more of a bad ass, introduce more interesting characters, cant have the games story be similar to the last 3 plot felt very similar for all 3 games last gen

And where did you hear they started working on it since Uncharted 3 released may I ask?

¬_¬

2015 would be too far out though. November or December 2014 would be the perfect time to release the next Uncharted considering that it will be the holidays and it would be around a year since the teaser video which is how long they usually wait between the initial announcement and game release. I would be surprised if it was pushed back to 2015.