Basically, all PlaysForSure devices should support the files: a very good move there. I have great amusement (and disappointment) in the fact Zune, Microsoft's own player, doesn't support it.
Obviously, downloads on to Macs... well, apart from downloading being a minor thing, it's understandable that it's taking time. It does make sense how the BBC would want control over the distribution and not have a special case where they have the content on iTunes for a week, rented like films...
and Linux, surely copy protection on linux is just a silly point in the first place? Here's my DRM! And here's the code I put it together with!
(Obviously, the solution is no DRM, and as much as I'd love that, content providers tend not to.)