It would be interesting to play in some of your one-hour-prepped games.
I would too. I have very high respect for the level of DMing skill at EnWorld (evidenced by story hours and some of your published works), but I also have very low respect for the average 'improv' DM based on my experience with them. I would love to see how some of this plays out because my past experiences bias me heavily against all claims of DMing excellence based on 'winging it'. In my experience with DMs who think they can 'wing it':
1) Challenges tend to scale directly to character skil and player action. Any clever plot by the player tends to create an improvised counter-plot or counter-measure by the villains. Creativity is actually punished. Traps tend to exist when searched for, but not when they aren't so throughness and caution is actually punished. Defensive magic comes into existance when players try to solve problems with spells. High level gaurds tend appear in response to the presence of fighters and so forth. You are better off pretending to be stupid than upping the stakes by being clever.
2) DMs tend to create the plot twist based on the player speculation that they favor. Thus, the players tend to get what they expect to get. Twists are created as the players invent them. The DM does very little work, and as a result does very little to surprise the player.
3) Objects and clues have no significance or meaning at the time that they are found. Significance and meaning is added to them later as the DM improvises. As a result, the players are effectively on rails - even if the tracks are being laid only a few minutes before they get on them. There is no real puzzle solving, per se. Riddles, puzzles, investigative problems, and so forth have no real depth if they are even provided for which is doubtful, because there isn't really ever a situation where you are really putting 'two and two together' and solving something. Secret doors exist because you looked for them, not as means of altering the flow the plot. NPCs gather backstory as needed and the game has no history. The evidence of no past action exists in even a simple form, much less as a wide web of effects and threads that can be picked up on.
4) Tactical situations tend to be virtually non-existant. Most encounters occur on open flat terrain or in stock rectangular rooms.
5) Maps tend to be very simple and predictable, or even non-existant as its just easier to run combats in the street or wilderness or in large halls that are effectively outdoors. Exploration is pointless because you always find what the DM wants you to find (or at best a random encounter which is actually preferable), and nothing less and nothing more, and sometimes you don't even find that. Sometimes you are just finding what you imagined you'd find and the DM is just queueing off your imagination entirely (random tables would be far preferable).
6) The game has no meaningful cosmology or depth of setting because there was no world building. The game world has no history, no philosophy, no meaningful religion beyond 'light' and 'dark', no meaningful ethics beyond 'white hats' and 'black hats', and villains are simply 'things you kill'. And that's actually the best case scenario, since in many cases the improv DM thinks he's being really clever and mature by making everything the same drab shade of gray (or more 'mature' still, the same shade of black).
In short, I get frustated with the sorts of games for the very same reason I get frustrated with TV series that are improvised in the same way - Lost, X-Files, The 4400, new Battlestar Galactica, etc. - with no clear plan from the beginning but the soon self-evidently false promise that the 'Truth is Out There'.
Now, I'm not saying that 'winging' it isn't something that ought to be in the DM's tool bag. I very much agree with those that say that lists of names and random tables are some of a DMs best friends, because everyone has to be able to wing it some. And I've improved a few sessions in my time as well, but usually based of some past brainstorming that never got formally written down. Every once in a while a complex plot complete with events and locations storms into my brain in an instant fully formed like Athena, and I have more ideas that I can write down, but thats rare. I have the impression that some of you can do that all the time, and if its a skill, I sure want to learn it.