Chaos Rumours on the horizon: Does AI13 Drop any hints?

Just today, I have read up on rumour blogs about Chaos Space Marines receiving a new Chaos Marines faction that is perhaps in the works. Seen as though Chaos is like my thing, I thought I would share my thoughts with you on what I think/ guess they could be, if they will exist at all. Please note, take the salt by the bucket load: This is all just theories for now.