Forgeworld has a Tyranid update planned, and of course that means some new units, along with the old. Forgeworld has a lot of models that really need to be updated for Tyranids, as some are now two editions old. Here is what Forgeworld said.
Please remember that this is a letter from Forgeworld in response to a question about Tyranids.
via Dakka, in a response from Forgeworld.
When we mention that we will be updating the rules for our Tyranid models this means that for some of our Tyranid creatures there are no 6th edition rules for them although we did publish some in the 2013 IA Apocalypse book for the Scythed Hierodule (the Barbed version is in the GW Apocalypse rulebook), Malanthrope and some extra rules for the Heirophant Bio-titan. Several years ago we published the IA 4: The Anphelion Project book which was a campaign book that detailed all of our Tyranid models at the time. Since that time at least two editions of the 40k rules and Tyanid Codex have been published so an update of this book is sorely needed, which is what we are planning.
Although there will undoubtedly be some new Forge World Tyranid models in this book we can't reveal any details at this point.