thats pretty surprising, seeing it still holds viable in 5th edition without any regrettable short comings (beyond the useless special characters). i mean i was pretty wowed by the fact i can give everything in my army either a 6+ invul, favored enemy, a psychic hood ability and a free move before scout movements, or +1s -1i. not to mention the terminators can have both heavy weapons in a single 5 man squad and a dreadnought with tank hunter. im not saying those things are broken but they definitly still hold ground with the newest armies
personally i think dark eldar deserve a tune up since theyve been in the running since 2nd ed. i know people say the necrons do, but theyre not bad here, since we take out the phase out rule. and i think the grey knights were awesome the way they were, being able to show up in any space marine army or call guard and marine units into theirs is a really nice thing why ruin that and force out a pure grey knight codex?
unfortunately by the looks of things, daemons are the ones getting a new codex, with all the new plastic stuff appearing. it makes since, grey knights dissapear, daemons rise to power again, then new grey knights to put them back in their place