The big question is; will these be from existing Space Marine Chapters or new ones?
Away from the rumours for a minute, this image turned up this evening and is looking pretty close to the reports out there on the net right now. As you can see (if this image is in fact correct) they now have a longer assault rifle style weapon, with a new form of armour that is an obvious extension of the MkVIII more recently seen on the Deathwatch miniatures. Notice also the new Bolt Pistol, which is more like a mini Bolter and the comms pad on his forearm..
Now this image could be fake, but its the one doing the rounds, so hope you enjoy!!.