I know I said I wasn't going to traffic in rumors anymore, but I got some delicious tidbits from Brimstone, an Interwebs Warhammer Celebrity. His word is generally correct, so that's why I'm sharing it and not the whole new crop of rumors that's sprouted up.
Basically, the Trygon will have several head options and several tail options. One of the head options is a distended jaws, for swallowing. He said it would be called a "Mawloch" though the spelling on that is unsure (it also has not been seen yet in any Trygon photos). He mentioned a tail option as like a rattlesnake. It supposedly looks awesome.
There were some gameplay rumors for it, but they were not from Brimstone, so take everything here with a bit of NaCl. It will not function like the Apocalypse Trygon, so it can't deepstrike into close combat. It supposedly will have its own mishap table. Raveners can enter from behind it, and assault the turn they arrive. Both Trygons and Raveners will be able to burrow and re-appear via deepstrike.
Non-Trygon stuff from Brimstone: Gargoyles are indeed plastic and will come 10 to a sprue. They will use flying bases, but because they are plastic are much more stable.
Raveners are plastic as well, and come three to a sprue, and supposedly six to a box.
That takes care of our three new plastic kits. The three metal ones are a Venomthrope, Hive Guard and a Pyrovore as we have price listings for them.
Well, we are less than two months away and the only pictures we have are a Venomthrope and the cover. The new battleforce ships in 14 days supposedly, and we have no idea what's in it. Let's hope some of those new models are in it!