Well, I'd say, by default, what has already been set by precedent -pairings of two different runs in one line, such as "Black Knight/Yellow Claw."

Or: it could totally break precedent, and have a line that combines material from multiple differing lines.

Or: it could be added into other series as bonus material.

Seems like the 1st option would be most likely, being the most simple, and having the virtue of "finishing" the "line(s)" as quickly as possible.

On a related note, I'm still "dying of curiosity" as what's going to happen ("breakdow-wise"/"mapping-wise") with future volumes of USA Comics Masterworks... based on what Cory said in this thead: http://marvelmasterworksfansite.yuku.com/reply/277382#reply-277382