IANAL, but I highly doubt this is automatically the case. The lack of written contracts is troubling, but I suspect that a competent legal team could demonstrate significant enough contribution to warrant joint ownership, assuming such contributions exist.
IANAL either. Arrington says they contributed IP to the project -- that's pretty significant. I'm curious to find out exactly what it is they contributed. They do have the staff for it.
As for marketing, so far it's consisted of a few blog posts. They do blog posts for other products too. I don't see much in the way of any ownership coming from that.
