Crusader Kings is a niche game even inside the niche market that is grand strategy. Look, they only even got the 5000 or so Facebook joins out of the 20000 after which they said they would announce CK2. Of course, there's good reason to assume they were going to do it all along and simply did that facebook thing to create hype, but the point is proven, the player base is small. What applies to HoI3 and V2 applies even more to a small game with less expected profits.
So since it's not plausible to expect Paradox to give us both lots of depth and width at the same, I think we should encourage them to choose depth. I'd rather have one top-rate sandbox than several mediocre ones.
I'm absolutely sure CK2 is expected to outsell Victoria 2. Just as CK outsold Vicky.
More to the point, Paradox is giving a longer development cycle to CK2, similar in length to their EU games. Games like Vicky2, Rome and Sengoku did not see nearly as much attention.