TLoU team will begin working on their next game (sequel or not) and target for it to come out a year to two after whatever the U3 team is working on.
All that said... I really want Uncharted 4! Something that changes the formula a bit and launches a new trilogy.
@aureila: THANKS FOR THE SPOILER. jeez not everybody has played the game why woulds you spoil it in a public forum?
What spoiler? the fact that some people didn't like the ending?
I predict we will see a new Uncharted, on PS4, by no later than December 2015.
It will happen, just be patient. There are plenty of other games out there to play, besides the Uncharted franchise.