I don't really do things like this that often any-more as 40K new releases no longer excite me particularly...however I was asked the question so here's the answer...more or less...
Tyranids are after Space Marines
Codex Launch date: 1st Saturday in November...probably
New Minis:
Tyranid Prime - Finecast
Harpy - Roughly size of the heldrake. Pretty much looks like the picture in prior codex.
Doom of Malantai - Clamshell package
Parasite of Mordrax - Clamshell package
Termagant - Sprues re-cut for more options (some chatter says Genestealers)
Mycetic Spore
New "Big Bug" kit (Because every fucking army needs a vastly overpriced book-end apparently) Tyranids will be receiving a large plastic monstrous creature - the new kit in comparison to the Tyrannofex will have similar size ratios as the Wraithknight to the Wraithlord
New Rules:
Altered FOC - Apparently to help counter the lack of Allies. 3 HQ, 4 Elite, 6 Troop, 4 Fast, 4 Heavy. Purchasing the 3rd HQ choice unlocks the extra Elite, Fast, and Heavy slots.
The previously mentioned "BIG BUG" – Larger than Tervigon sized HQ unit. Oval base, hunched over, but wider. Has 18” synapse. Psyker 4. Prime version: Grants FNP and Counter Attack to Nids in 12.” Stats like Tervigon, except 2A, Shadow in the Warp
Pyrovore - Gains Torrent and a steep points reduction.
Hiveguard - Gain Skyfire - New weapon upgrade option (available to a handful of units) that grants skyfire with an "enhanced ability" to ground FMCs.
Termagants – Gain Fleet. New 10 unit box. Includes options for Spike rifles and Strangleweb. Curled tails. No rippers on sprues.
Tervigon – Upgrade options for Termagant spawns to give them full options, but they are quite pricey.
Tyrant Guard and Hive Guard - Dual-build plastic kit. 3 models. All options for either unit.
Lictors – Small point increase, gain new “Surprise!” rule (all shots against Lictors the turn after they appear are snap shots). DeathLeaper now an upgrade character.
Carnifex - Significant cost reduction
Harpy – Big overhaul. New model/dual-combo kit, Flying Monstrous, Sonic Screech combines with Vector striking. Additional Spore Mine Cysts may be purchased as upgrades. Default Stranglethorn has new upgrade options.
Ymgarl Genestealers - Special arrival rule is shared with the Lictor, may now purchase standard Genestealer biomorph upgrades.
New Flyer - Fast Attack choice, the alternative build for the Harpy kit.
Tyranids will get a massive overhaul with Psychic powers. Look for many new non-overt force powers that represent the chilling, horrific, warp-stifling power of the Hive-mind. Two new Tyranid psychic powers lists. One list is destructive powers, one is augmentative powers. More existing units will have the option of manifesting Psychic powers.
Aside from a few old chestnuts, look for almost all new Tyranid enhancing abilities, and other new chilling and damping abilities to use on enemies of reflect the horror, hopelessness, and dread of fighting the swarms under the psychic interference of the hive-mind. Look for concepts such as dampened psychics for opponents mixed with bio-enhancement powers to bolster the swarms.
Shadow in the Warp will remain in the codex, but receives an overhaul that is apparently going to piss many people off....that could mean anything though...
That's what I have so far.
Thoughts and comments are (as usual) most welcome.