cparsons,
Yes, our latest version is MyEclipse 2013 SR2. Please check this document which will walk you through some key changes and new features in MyEclipse 2013.
Regarding eclipse versions, MyEclipse 2013 is based on Eclipse 3.8.2 (Juno). MyEclipse 10.x is based on Eclipse 3.7 (Indigo) version.
Regarding ‘Arduino (C++) coding’, we haven’t tested this plugin in MyEclipse. Can you recheck if the plugin is compatible with the base Eclipse version of MyEclipse ? Ex : If you are working with MyEclipse 10.x, then the plugin must be compatible with Eclipse 3.7. If the plugin is compatible and working fine with base eclipse, then it would work with MyEclipse too.
Hope this helps.