The Marantz or Denon options should partner well with the B&W setup.
As for Rotel, they don't tend to update their models as often as the Japanese stuff. As Rotel and B&W are from the stable and B&W are one of the Airplay partners, it would not surprise me if the next Rotel models had it integrated but then again, they've not exactly been renowned for adding "bells and whistles" to their equipment. They tend to concentrate on the basics, including sound quality, which is rather important after all.
I haven't seen or heard Airplay in operation yet but I hope it's better than the other networkng functionality that has been added to AV Receivers. It seems to me to have been added as an afterthought. Just as an example, it is very slow and clunky on my Yamaha receiver. Selecting a song takes forever and I don't even have a nice iPod or Android graphical app to look at to take my mind off the fact it takes forever. I'm sticking with my Squeezebox for now, which I am more than happy with.
Anyone used Airplay? What does it offer over other streaming solutions integrated into AV receviers other than simultaneous multi-room? Can you stream music to one room and radio to another for example or do you have to have the same music in all rooms/zones?