I already have a pair of painted plasma hatcher eggs from my Mycetic Spore days, but I can see myself getting a Tyrannocyte or 2 anyway because they open up the army so much. Heck, I can even see uses for the Sporocyst and Mucloid Spores. If I did get the box though, I'll probably model the Tyrannocyte as the Sporocyst though because it looks super-fragile on its tentacle legs, and I might get some Mieoctic Spores from Forge World to proxy as Mucloids.
As for the other things, I can see myself getting a Toxicrene at some point, if only to paint the squashed Terminator like my opponents' chapter.

I don't really need more Venom/Zoanthropes though, so I might just ebay the Neurothrope if the rules are up to snuff.