This includes also Beta version of SP2 for SharePoint Server 2010 and SharePoint Foundation 2010.
As with all Beta products: don't use it in production. Also be aware that an upgrade from SP2 Beta to the final SP2 might not be possible or supported. That means you need to ensure to only evaluate this Beta version in a test environment which you can reinstall after the evaluation.
See here for the official announcment:
Any time frame for the actual final release?
a release timeframe has not yet been announced.
Since SP2 is currently in Beta testing I guess the patches of the SharePoint 2010 April 2013 CU are not included. Given that SP2 will be available in the near future, does it make sense to patch the system with the April CU now?