The Tyranid codex is now up for pre-orders for both the physical book and digital releases. Of course alongside the Digital Release pages, there are some nice previews of this codex. There is also the new release video as well on youtube.
The images shown here are released images from Games Workshop.
Here are the links were you can view these and the other previews for the codex, of course this is also were you go to place your orders.
Release Video on Youtube
http://www.youtube.com/watch?v=Hxy29MCeYt8#t=99
ebook
http://www.blacklibrary.com/games-workshop-digital-editions/Codex-Tyranids.html
Ipad Interactive
https://itunes.apple.com/gb/book/codex-tyranids-enhanced-edition/id786433696?mt=11
Tyranid Pre-Orders
http://www.games-workshop.com/gws/catalog/armySubUnitCatsLarge.jsp?catId=cat440160a&rootCatGameStyle=wh40k
The Exocrine is by far my favorite models in the new line of releases, but the Hive Crone and Harpy look like they will popular flyers.
Also found on the previews are both Boneswords and Hormagaunts. Hormagaunts are listed as 5pts apiece, while Boneswords are indeed ap3 with instant death.