Samsung is working on preparing Android 5.1 for the Galaxy S6 and S6 edge, as well as the Galaxy Grand Prime. Lollipop is also set to be heading to the Galaxy Core Prime and Galaxy Mega 2. Future updates for all!
According to SamMobile's source, it appears Samsung is continuing with plans to really knuckle down on device updates and keep everyone on the latest version of Android. Unfortunately, there's no word as to when any of the updates detailed will roll out to consumers. Also, no news yet for the Galaxy Note 2.