Today we have some rules bits that give you what's called an Apex Biomorph. It appears you get to select one per detachment of Tyranids, and the powers range from Eternal Warrior to increasing the power of boneswords.
From the information below, it appears someone may have seen the codex with these powers, but I cannot verify that.
Please remember that these are rumors
via an anonymous source from the Faeit 212 inbox
Apex Biomorphs, max one of each per detachment:
1. Synapse range is reduced but grants Eternal Warrior. Can be taken by any HQ (not Troop Tervigons or HS Trygon Primes).
2.Twin boneswords, AP2, for every wound inflicted on a 5+ the model regains a wound. For Primes and Tyrants. Regular boneswords are AP3 by the way.
3. Virus spore barrage (Ordnance, Poisoned 3+, unlimited range, one-shot, the template remains on the board until the end of the game).
A bit hazy but saw a flamer in there that could be taken by Tyrants and
Tervigons only (AP3?) and a 3+ carapace that grants a 2+ and EW if the
model didn't run/glide.