well, so far we know nothing about the new stratagems, special craftworld rules or relics other than the (rather mediocre) craftworld Iyanden relic. While that relic makes me sad (I have such pretty yellow and blue models, I'm not gonna put d3 mortal wounds on them! I did expect this coming out.
I mean, they have marine chapter tactics, forgeworld dogmas, and whatever the guard equivalent was already. The only codeci they haven't used this one are death guard and grey knights - which is likely because they are already specialised as it is.
I fully expect the tyranids to get hive fleet evolutionary digressions, and so on. I think it would be nice from a fluff perspective, but of course, people will still be going "oh, but this other rule is much more advantageous... these red-painted guys with teardrops and wings everywhere are actually raven guard!"
So yea, while I like the idea behind it (as I love more fluffy additions to any army), it will of course just be used for rule advantages as ever.
Edit:Now the
Iyanden focus is up. I'm not sure what to think of it, though I'm happy my wraithguard and lord will toughen up a bit, and certainly happy the spiritseer has become more viable.
I'm just not too sure of the value of the iyanden attribute. But well, we'll make do.