So obviously I bought the remastered Riven within hours of its release. So far, two comments:
1. It looks absolutely gorgeous, somehow preserving the original game's visual depth while switching formats to full-3D movement
2. They have changed the puzzles! How is this allowed?!
The one disappointment - which you pretty much knew was coming - is that the FMV performances from the original game couldn't be ported over. Instead you get the old voice performances with 3D-animated characters. It's not as good, but probably the best you could hope for.