Today a small update was pushed which enables you to launch the player multiple times on one computer and at the same time as playing a game via Steam.
To do this, you have to execute the .EXE file directly from Windows - not through Steam.
If you right-click VSXu Player and select "Properties", you can find the tab "Local Files", if you click "Browse Local Files..." you should get an explorer window for the directory where VSXu has been installed. (Or if you know where your Steam library is - just go there with windows explorer.)
Once viewing this directory, double-click the "vsxu_store_player.exe" to start it.
Now it will still detect Steam and integrate with it and at the same time free up Steam for launching other things.
Creating WIndows Shortcut to VSXu Player
Being able to start it like this means you can also create a windows shortcut to it - for inclusion on desktop or task bar for instance.
Running a game and VSXu at the same time
This technique also enables you to run VSXu and a game at the same time - just don't start VSXu through Steam at all, but through the exe file directly and then launch the game on Steam like you do normally. Useful for the Streamers out there!
What was changed?
Since this is not a change in the code, the version number is still the same. All that was done was to add the file "steam_appid.txt".