So it looks like ND delivered a very good Remaster but all the "60 fps locked" statements done before on forums (not to blame people, Twitter from ND staff was the reason) seems now gone like the wind...
"Shadowmaps get a 2x detail boost, but the quality in relation to resolution remains unchanged - those dynamic real-time shadows can look pretty low res on PS3, and they still do here - and contrary to reports they appear to remain the same, with identical cascade transitions if you toggle the game to run at the optional 30fps."
"However, while its last-gen origins are at times obvious, there's no doubt that The Last of Us Remastered can look simply sensational. The boost in resolution combined with the enhanced textures emphasises the sheer class of Naughty Dog's artwork at all times."
"To answer the question everyone's been asking, frame-rate isn't locked to 60fps"
"Problems can kick in during busy combat scenes, and just like the PS3 version, particles and transparent effects in particular can take their toll - the first confrontation with a fungus-spewing Bloater sees frame-rate hit a minimum of 48fps."
"Frame-rate is mostly in 60fps territory for the duration, but just like the single-player mode, there are dips in the heat of the action. Our lowest reported reading came in an enclosed room with multiplayer games and saw frame-rate dip to the mid-40s"
"Titles like Tomb Raider: Definitive Edition were built with scalability in mind across a vast range of potential playback platforms while the development effort on The Last of Us focused entirely on PlayStation 3 - so with the remaster, enhanced texture detail, effects precision and substantial boosts to physical and temporal resolution are your lot. Some scenes can look rather plain, while others look absolutely spectacular, but the one thing that is constant throughout the experience is that gameplay in The Last of Us is golden."
"In summary, is The Last of Us Remastered truly next-gen before its time? In many ways, yes. A defining technological statement for the PlayStation 3 transitions across to PS4 very well overall, but the big takeaway from our experience is that there's more to a game's next-gen credentials than the quality of its pixels alone. Gameplay truly is king and you'll struggle to find any game on PlayStation 4 or Xbox One that matches up to the sheer quality on offer here. If you're new to PlayStation and haven't played The Last of Us before, it is recommended without reservation - you'll get more value out of this game than the vast majority of full-price PS4 software. And if you've already played it on PlayStation 3? We'll have answers for you on that front tomorrow."
http://www.eurogamer.net/articles/digitalfoundry-2014-vs-the-last-of-us-remastered