I bought The Last Guardian and have played a couple of hours. I'll get the negative out of the way first - the control and the camera are the two worst things about it and what really makes it feel dated. It just shows how far we have gotten in the years since they started developing it.
However, everything else is just as great as the previous Team Ico games.
Fantastic atmosphere, just as minimalistic and down to earth as before but with a strong sense of depth and history. Interesting mechanics, where you basically befriend a large Tamagotchi.
Trico (as he's called) really is quite adorable but still quite scary. But most of all - he is really well made. Everything, from the way he moves to his roars and his behaviour, just feels real to me. There's actually a "pet" button and I use it all the time when he has done something good.
If you were even slightly impressed by Ico or Shadow of the Colloseus, then pick up this game! It's a wonderful sequel.
(Well, it's not really a sequel, as for as I know. But it's the same style.)