My most important question, does the sound still play when you close the app?
I think you need a Google Play Music subscription for that.
Please Google don't put the same Material stuff on iOS. I already dislike it in apps like Drive..
It's already here, I opened the YouTube app on my iPhone yesterday and it looks pretty much exactly like this, only with the tabs across the bottom. Looks pretty good actually.
First screen of the FTUE has this big compass on it. The big compass isn't centered. I don't know any more :-(
64 px on the left hand side and 50 px on the right hand side.
I wish they updated the iOS version with a new interface as well. The burger menu is just frustrating to use and you have to use it to go to the 'my subscriptions' page, which is the only page I use in the app basically.
It was updated on my iPhone 6 a couple of week ago. Personally, I like the older (and the current on most if not all iOS device). I'm not a fan of the too much red and the removal of the slide menu.
But after I've installed the iOS 9 PB, the new YT app design magically disappeared to be replaced by the older one. I'm pretty sure Google is currently testing the design on iOS and if you're one of the lucky (or unlucky ones- depending on your preference), you'll see it on your iPhone as well (not sure about the iPads).