I noticed today in the update to Last.fm that whenever you press the pause button, iPod.app immediately takes back the music controls. Seems like a similar situation to Airfoil Speakers Touch: as soon as the audio stops playing, the app is suspended and you have to switch to it to start things up again.

The same is not true of Pandora.app. Tell the device to pause Pandora, wait a minute or two, and you can still un-pause Pandora. It'll continue to touch the network to get subsequent songs.

Does this mean Pandora is leveraging something to which you don't have access?