I'm thinking we're looking at 30 card decks for each faction plus enough neutrals to fill out to an ok deck size. Whatever gets us around the 200-220 card mark.
The rogue trader looks weaker the more I look at it. It needs two turns to be profitable and dies very easily. The void pirate is a little better, but not much. I don't think these guys will see much play once players get their second core set. Shielding them seems like a waste. This is only based on what we've seen so far, though.