As of 1 March 2015 the BBC has switched off its WMA streams and migrated all of its stations to AAC streamed over HTTP Live Streaming, a format and protocol not supported by the SoundBridges.
At the same time the BBC started providing MP3 streams which are compatible with the SoundBridges.
All BBC stations listed in Radio Roku have been updated and should play on the SoundBridges.
While this is good news for all BBC listeners, there's also some bad news:
a) According to the BBC's Jim Simmons the MP3 streams will only be available for another year or two. Once these streams will have been switched off, the BBC's stations won't be available on the SoundBridges any more and there will be no way to get them back.
b) At the moment only the international streams are available as MP3. These streams don't contain sport or other rights restricted material, therefore you won't be able to listen to such content even if you live in the UK. According to the BBC's Andrew Scott this might change in the future, but there's no concrete timeline.
c) The MP3 streams seem to be less reliable than the WMA streams so re-buffering might occur from time to time.