Pandora and iheartradio (which was also missing) are a bit different than the rest of the music sources. Unlike SHOUTcast, etc, these two are *not* built in, but rather downloaded upon boot. This allows us to change them without having to do either a firmware or Control Panel update. Ideally, some of the other music sources would also be migrated out of the device to give us similar flexibility to do updates.
We've been doing a lot of server reconfiguring lately in order to prepare for (a) scaling to handle a *lot* of devices that have been sold as Christmas presents but won't be activated until then, and (b) a couple of new products that will be coming out. it's tricky to do that while maintaining a running service serving data to (insert big number here) devices in the field.
What happened is that one of the virtual hosts was slightly misconfigured, and we fixed it. Unfortunately, this particular host served up the Flash movies that implement that Pandora service on the client.