I think that if they re-do them a little bit they`ll be quite competitive, seeing how 40k seems to be more and more about short range/meelee.
Last chaos dex took out one of the most powerfull static armies in the game while the new ork dex added a new level to meelee swarms
You can realistically run 60+ biker orks in a 2k game now
not to mention the insane ammount of normal orks you could fit in there.
Template weapons are the only thing stoping them, that and lots and lots of attacks