On what planet would Jennifer Hudson wait for a revival of Caroline, or Change? Not only is that piece far less well known, but I can't think of a worse part for her to play.
Anyway, I don't think very highly of this show, but I think Hudson's right to play Shug rather than Celie. This way, not only does she get some great material, but the entire show won't be on her shoulders, so if she sucks it ends up being less pressure.
I am a firm believer in serendipity- all the random pieces coming together in one wonderful moment, when suddenly you see what their purpose was all along.