I played a bit of the new Tomb Raider at the Eurogamer Expo last year, and attended a talk by the devs, and I can say that its similarity to Uncharted is pretty superficial. It's a different beast. For one thing, Uncharted is pretty much a funnelled sequence of action set pieces (that's not a criticism - I ADORE the Uncharted trilogy). TR has a bit of semi open world exploration, RPG-lite character progression, and even a crafting system if I remember correctly.
I'm not sure it'll satisfy any hardcore Tomb Raider fans because it's quite a departure, but they're doing something different with a franchise that's been going through the motions for a *very* long time, so I do hope it works out. Looking forward to it.