I gotta disagree. This looks amazing. The ability to free roam this world is huge on its own. From the previews I've read there are tweaks to the world and new puzzles sprinkled in. This looks like a great way to introduce a new generation to Riven without tarnishing the original.
Plus the originals are indeed still available to enjoy if that's your thing.
Looks gorgeous, like the original. I'm curious if it'll be harder than the original, being in full 3D. With the ability to freely run around everywhere, it might be easier to miss something than if you only jumped between predetermined points. Maybe not, I can't remember if everything important in Riven was visually distinctive, or if there are things hidden in the background that are easy to overlook.