Looks like it's releasing on PS4 and Xbox One.
Old instruments (minus the keyboard/pro instruments) should be making the transition, along with most, if not all previously released tracks.
While I haven't really touched my Rock Band instruments in a few years, it's nice to hear that the series is coming back.
I have a lot of fond memories of getting together with a bunch of friends, and playing these games for hours on end.
Source:
http://www.ign.com/articles/2015/03/05/rock-band-4-announced-for-ps4-and-xbox-one
