At long, long last, Sky Player Desktop is now available for the Mac, and very nice it is, too. The app's also been updated for Windows users.
I had a few issues getting going with it. Most of these seem to be because I was using Firefox with AdBlock. Initially, I was getting errors both trying to stream through the browser and trying to download using the Desktop app. The former was sorted by disabling AdBlock and the latter by using Safari to initiate downloads.
You use the web site for streaming stuff live and for queueing up downloads which get handled by the Desktop app. Downloaded programs play beautifully with the built-in player.
This is going to be great for my weeks working away from home.
Go grab it now (it's free) from the Sky Player site.