I would love a 3d camera in shake.
I think the reason nobody complains is because most of shake users works for big effect house, where resources are high. So when they need a 3d compositing package, they use flame or inferno, and when they don't need it, they use other package, like shake. Of course I might be wrong since I have no Idea how they really work.
For the do-it-all-one-man-team like my, I would love to have it all in on package. A nice tight integration with maya would be incredible. But it's not the case. So you find alternate ways of doing things.