hmm...looks fast and fluid.. but pointless. If I am playing a game.. I don't pause it to surf the net.. or to talk on skype. To each their own I guess.
I think your focusing too much on the apps they switched to. I'm right with you in saying that I wont be using Skype while I'm gaming, but I think the idea itself could be very useful to me in terms of improving my gaming experience.
I'll give you a couple of examples:
The Machinima guys will have an app on the X1 at launch that ties into whatever game you are playing and can offer you access to game tips, etc for that game. The demo they showed had it off to the side and you could pause gameplay to check out a quick video and then pop right back into playing. In a related idea, I could see myself pulling up IE for say a Gamefaqs guide to reference something. Being able to quick switch between this stuff makes that possible in a way that was far to inconvenient this gen.
The second example I would give relates to music playback. I find myself wanting to listen to my own music for some games and the idea of being able to switch to say the Xbox music app or snap it to the side in order to switch tracks, pick a new playlist, etc, is a step up from the way its handled on the 360.
I just think that with the right app, there are useful scenarios for users that add something to the experience.
Overall, the vid did show it was fast and fluid, allowing gameplay to keep running even when using an app. The fact that you can return to the dash without leaving the game is pretty slick, a big step up functionality wise from the 360.