I downloaded the Demo of PSN, and was pleasantly suprised. The first thing you notice are the graphics, they're stunning. The lighting, water, foliage look brilliant, as is the character animation. Little details include his clothes and hair becoming wet when in water, and him wincing when there is a nearby explosion.
Gameplay wise it actually plays more like Gears of War than Tomb Raider, and the game encourages you to look for cover when coming under enemy fire. Jumping from ledge to ledge is less anal than in the Tomb raider games, and it is slightly more forgiving.
Being a game from Naghty Dog it does have it's fair share of humour, for example when a grenade is thown near Nathan, he mutters "oh that's not good". It may be a more mature direction from Naughty Dog, when you consider their past two franchises were Crash Bandicoot and Jak & Daxter, but non of the charm is lost.
It did look look very promising, but with all the hype surrounding games now we're often left feeling a bit dissapointed when they finally do arrive. I'm glad to say this isn't the case with Uncharted. It's a PS3 exclusive, and at £32.99 you can't go wrong, I can't wait to get my hands on the full version.