SC Craftworlds: Looks sort of like SC Iyanden to me, though the War Walker's an interesting addition to the dead. Sort of glad to see a few more models (and less jetbikes), but unless Wraithguard get modified to Troops it's still the odd one out because it can't actually be fielded as a Patrol Detachment...
SC Tyranids: This thing looks like a bridge to/from the Genestealer Cults more than anything. The current SC's Gargoyles are an odd duck, but Genestealers got tossed into every game-in-a-box where GW needs an obviously evil alien ever since the days of the first Space Hulk. Not sure what gribbly the Nid players would like the most in their SC, but I'm guessing it's between Hormies and Termies.
On the positive side, it's a good addition to an existing Nid force with an obvious strategy - Trygon tunnels, Genestealers come out, surprise b***s** ensues. It's also a good way to get your hands on the horribly overpriced Broodlord.
Ask not the Eldar a question, for they will give you three answers; all of which are true and horrifying to know.