The only reason this is surprising to me is that I thought the game was pretty well finished by now but I guess they didn't really go full bore into development until perhaps the start of 2013 ? That would mean maybe a 3 year development cycle if you count all pre-production work. I'm going to wager it was originally targeted for a November release this year but various issues contributed towards that goal looking a bit too lofty.
Let's get into that just a bit shall we ?
The playstation 4 is selling very well even without an exclusive killer app.
Seriously , Sony is pushing a million + every month since launch and it doesn't like things are slowing down at all. The only territory it's not doing gangbuster sales is sadly Sony's homeland of Japan but that's an issue endemic of non-mobile gaming in general moreso than an exclusive PS4 or even vita problem. Since people keep buying consoles elsewhere, what reason does sony have to rush games out ? Rushing development leads to more problems and is also less cost effective.
Sony hasn't had a real PS4 exclusive hit game. By hit game I'm refering to that must have title that is both a critical darling and a sales success. Sony's first party published efforts have been mostly fruitful sales wise (although nothing has been HUGE) but critically ? Not so much. While I dislike score aggregate sites , it has to be at least a mild annoyance that all of sony's PS4 titles to date have been lacking in the high scores department. Knack 58% on gamerankings / 54 on metacritic. Killzone 73%/73 MLB 2014 83%/83 , Infamous 80% / 80, The Last of Us remastered 96%/95, Drive Club 70%/ 71, The Order 1866 64%/65. Worth noting that the 2 highest rated titles in there are also available on PS3. My point here is that , Sony really needs to make their next big release a FANTASTIC game , not just a nice port or a GOOD game.
2014 was a prime example that more time in the oven is better. Drive Club and Halo master chief collection both had sloppy online play and the latter was riddled with some pretty obvious bugs. Assassins creed unity was released at least 6 months away from actually being finished. Last fall there were a few titles that looked like they could have been better experiences with more time spent polishing them up or even just making sure they worked at all prior to shipping. As the saying goes - a late game that is good will be remembered for being good but a game that comes out on time but unfinished will be recalled as a turd.
You'll have too many games competing or your time and money as it is. Take a look at sales figures for the last 5 + years , every single year we get a new Call of Duty and every single year everyone buys it. Every single year we get a new assassins creed game and people keep buying those too. Same goes for Fifa and Madden updates. This year we are also finally getting Metal Gear Solid 5 in september and if you own an xbox one - halo 5 and forza 6 will be out. Nintendo might even surprise us and actually finish the new zelda in time for christmas. What I'm getting at is there are a wealth of big name games coming september through december just as there always is - why even compete with that if you don't have to ?
Uncharted 4 will be a much more polished and probably fun game now. I'd be willing to be money that ND COULD have finished this game for christmas but it would have had more than a few compromises- maybe the framerate wouldn't be stable, maybe the single player would be a touch buggier , perhaps there's a stage missing ? Replaced with more cutscenes ? maybe the multiplayer options would be barebones ? Who knows , what I'm saying here is that the game will be a more finished and enjoyable product with 3-5 months more development time.
The door is now wide open for the back half of 2015. Sony can fill this void with anything now. Many people have expressed interest in a remaster of uncharted 1-3 , well what if that comes out and it has the PSvita title in there all in 1080p at 60fps with the multiplayer being a playable beta for uncharted 4s multiplayer ? What if that makes it out this summer now and you've got 6 + months to play through all 4 titles before diving into the new one ? Or maybe even Last guardian is just going to pop out of the wood work and be ready to go later this year ? Who knows right ? This gives sony more options though.
I'll just add my personal thoughts on top of this - I only finished uncharted 1 ,played all of 20 minutes of the second game, didn't touch the third and while I have golden abyss flagged on my vita I've never played it. My interest level in uncharted 4 is perhaps a bit smaller than most because of this but BUT , were I given the opportunity to re-experience all 4 titles in 1080p on my ps4 ? I'd probably be much more invested in Uncharted 4.