I have to raise my eyebrows at the "who is asking for this" types of comments. We are talking about game geeks. There are people who sink great amounts of time and money into minis and physical terrain, costumes, luxury versions of adventures (Beadles and Grims), etc. VTTs are no different. The VTT itself is a hobby for many people. People put a great deal of time, and sometimes money, into foundry mods to run the game they want. I don't even think the 3D VTT has to be that easy to use to gain a sizable audience if it can provide tools for certain types of geeks to turn dungeon building into its own hobby.
Personally, as I said above, I'll likely only be attracted to it for official WotC content all fully prepped and, even then, only if they finally release a VTT that properly gets all the automations done right. If it does that and isn't too wonky to use in game, then I might even appreciate the 3D. Dealing with elevation in most current-generation VTTs is rather kludgy. Something that can represent actors on different levels in the 3D environment and flying could make running the game easier. If they get all this right AND have building tools that don't have too high of a learning curve--who knows, perhaps I would be convinced to use it to build my own encounters.
What makes me more skeptical, however, is that I need to see how they will handle fog of war, especially for large area exploration. The demos look like they could be nice for set-piece encounters, but I would like to see how they would handle, say, putting in the entire Dungeon of the Mad Mage. Which raises another potential concern: how are they going to price storage and how will performance be affected by large maps. One reason that I ditched Roll20 after testing it for several months is that even if I were willing to pay the highest subscription rate, I still didn't have enough storage for my current campaign. And a single-level map from the current mega dungeon I'm running would grind Roll20 to a halt.
So, I'm not very optimistic that WotC's VTT is going to be the correct tool to manage my entire campaign in and I don't see myself paying subscriptions for two VTTs (Foundry for most things and WotCs for set-piece combats). That leaves me with being cautiously optimistic at using it to run WotC official adventures, which will hopefully be built and well tested by professional developers and designers.
And who knows, if I ever get to run games in person again, I would happily go back to using the free Map Tool program with a horizontal display and minis. It is so much easier to run home-brew and sandboxy games in than any of the major VTTs--and much less expensive.
