Is it possible to force an AVAudioSession to output to the headphone jack even if an HDMI accessory is connected?

Question

Is it possible to force audio through the headphone jack even if an HDMI adatper is connected?

I see that iOS 5.0 now has constants for multiple Audio Routes:

const CFStringRef kAudioSessionOutputRoute_LineOut;
const CFStringRef kAudioSessionOutputRoute_Headphones;
const CFStringRef kAudioSessionOutputRoute_BluetoothHFP;
const CFStringRef kAudioSessionOutputRoute_BluetoothA2DP;
const CFStringRef kAudioSessionOutputRoute_BuiltInReceiver;
const CFStringRef kAudioSessionOutputRoute_BuiltInSpeaker;
const CFStringRef kAudioSessionOutputRoute_USBAudio;
const CFStringRef kAudioSessionOutputRoute_HDMI;
const CFStringRef kAudioSessionOutputRoute_AirPlay;

I also see that iOS 5.0 supports a new property called kAudioSessionProperty_OutputDestination that is read/write:

kAudioSessionProperty_OutputDestination
A read/write CFNumberRef object that indicates the audio output destination, from a USB         audio accessory attached through the iPad camera connection kit, that you want to use.
The value must be one of the identifiers provided as a kAudioSession_OutputDestinationKey_ID key as part of the kAudioSessionProperty_OutputDestinations array.
Available in iOS 5.0 and later.

Questions:

1. Is the property designed to let me force the output route?
2. The docs mention a USB audio accessory. Will this work when no accessory is connected, or when a HDMI cable is connected?
3. Is there any sample code showing how to set this property correctly?

Thanks!