The hotels I've seen them in (in the US) have been Hampton, Hyatt, and Mariott. I might've seen one in a Sheraton, but don't quote me on that (and if so, only once). Definitely seems to be per-hotel rather than brand-wide, though.

Yeah its a game changer. Marriott brand is rolling them out, and Hyatt has them too. These are massive portfolios now, and will save them from getting screwed over continually by Apple changing the docking station ports.

For now Chromecast just being there and part of the TV will let users do what they want with music and now this.