Demons Run: Two Days Later [update] and the US iTunes store have listed a new extra for Doctor Who, Season 7 Part 2. Titled, The Battle of Demons Run - Two Days Later it has a running time of three minutes and has the following synopisis:

In the aftermath of the battle of Demons Run, a battle-scarred Strax lies dying on the floor - or has he just fainted...

You can check out the listing on Amazon HERE, where it is also available to download and it's also available as part of the Series 7, Part 2 subscription on iTunes (in the US at the time of writing). Thanks to Corey LeChat for the heads-up!

ETA: The episode is now available on the UK iTunes store.