I think you’re correct, drpix. I think that Roberts is taking this case because he knows the Court will rule in favor of the gun owners, and he wants that to be settled law.
No he's taking it because there is a split in opinions in two separate circuits. The Supreme Coutt is more or less obligated to take the case to settle the law.
I am not optimistic. There are only four justices who give a damn about the what the framers thought about this amendment and what the original intent was. This one could go very badly for our second amendment rights.