The comfirmation of these rumors come from Brimstone, Harry and Hastings on Warseer. That's as reliable as it gets in the world of GW rumors. ( And I Shamelessly Copied and Pasted from the Bolter and Chainsword post.)
Here is the current round up of rumors that we have so far. I will keep this post updted as new info becomes available. New info will be in this color.
The Space Wolf codex has an October release date.
LC's are called Wolf Claws in the new codex, you can choose to either re-roll to hit or to wound.
Canis Wolfborn is the new SW SC; He's riding a very big wolf in a not so weird way as that sounds. Let just say those bloodcrushers look like grots!!! Also Canis is power armoured and has 2 wolf claws. The wolf has some cybernetic bits on it.
IIRC taking Canis also allows you to take two cav choices, 1 can be SW mounted on wolves, the other is just wolves.
Njal Stormcaller returns to the Codex with a new model, holding a gnarled staff out before him.
Bjorn the Fellhanded returns to the codex.
All special characters have been resculpted.
Wolf Scouts will remain the same and they also have the option be mounted in a Land Speeder Storm
There will be 2 main plastic kits, however 1 of them can be used to make pretty much every SW troop choice by combining the oooodles of spares on the sprues with normal vanilla marines kits (e.g. a box of devastators plus the extra from the sprues will make your Longfangs. IIRC there are around 30+ heads on the sprue!!! there may also be a special vehicle, but I'm not sure if it's a complete kit or if there will be an upgrade sprue to add to the existing kit.
There's also a funky new way of kitting out your characters called Sagas, it is similar to the Vampiric Powers used by WFB VC, but IMO much more fitting for SW, and very fluffy, in fact it is IMO one of the best ideas GW have had in ages. You choose "sagas" for your characters, perhaps someone with Saga of the monster killer (I made that name up by the way) may be better at killing monsters (high strength things) in some way, although there could be drawbacks to this as he may need to kill so many of such things per game to continue his saga......
Space Wolves gain access to an Assault Cannon Land Raider variant.
The current options for jump packs are going to change. BTW Jump Pack marines are called "Skyriders" in SW Codex.
The only currently unconfirmed rumor comes from BoLS, they say there is a metal Wolf Guard Terminitor bodyguard box due out.
Plastic Wolfguard Terminators; they are ambidextrous, ie they will have right and left handed weapons options like Stormbolters.
When asked about Pack size, Brimstone says that Space Wolves will be even less Codex Astartes than they were before.
The Space Wolf army is themed on movement. Move, Assault, Fire, Move, Assault, Fire, etc. Its not meant to be a static army. It's also an army to be filled with lots of Troop Choices.
13th Company are not officially dead but are special choices based on your army. This Im not clear on whether they are a "Legion of the Damned" choice, or something based on the HQ you purchase.
Pack Leaders are now unit upgrades and are not purchased from Elites. This Im not 100% on either.
Grey Hunters are strongly rumored to be able to take a second special weapon in their squads. That is something that I don't understand why Salamander's don't have anymore.
Long Fangs "May" be able to have some sort of a special rule where they can move and fire, but not assault.
Blood Claws have been re-worked to level with 5th Edition in respect to "Bezerk Charge." What it is Im not sure.
