It would be interesting if there was a new campaign from one of the other factions.  Allowing players to use a non imperial hero like tau, or tyranid.  It would be fun to massacre imperial space marines and guardsmen with a  tau firewarrior. could even create a tau ship and bridge to serve as a base.  I mean something new from the usual "Kill the xenos", "for the emperior" routine.  kinda like the problem with disney and the failed new star wars trilogy that even George Lucas calls mundane and boring.  You gotta branch out and take risks every now and then.  As it stands warhammer 40k is easy, monotonous, and boring.