Hah, just finished watching that video a minute ago.
And yeah Android Lollipop looks great. Seems like the cleanest and most visually impressive version of Android yet. I'll be getting the Nexus 6 on release, so can't wait to fire up Android 5.0 on that bad boy.
Screen pinning looks like a great idea, however I was hoping there'd be a passcode or pattern unlock to show up before it removes the pin. If someone knows that you have to press the back and multi-task button to remove the screen pinning, then it kind of defeats the purpose. I would have liked it if when you press the back and multi-task button, your pattern/pin security pops up for you to enter to remove the screen pinning mode. However if you don't have a lock set, then it won't come up with one.
Only a minor thing, but would like it to be addressed in the future.
Also I'm looking forward to a stack of app updates from Google. Gmail, Maps, Calendar, Keep and particularly the new camera app. I'm not a huge fan of the current Google Camera app as I feel it's pretty lackluster, but up there's going to be a big update for it in 5.0.