I'm thinking it's a reshaping of the line, personally. Taking a step back, and looking at where they've got to adjust things, and giving some of the previous waves time to catch up maybe, while getting the Revenge stuff out.
Just a guess, could be completely wrong. It just sort of fits though, to me. Everything's in disarray, they're aware, and right now SW isn't the forefront of the toy aisle, so it's maybe a good time to just attempt to right the ship internally and use 2012 and TPM 3-D as a clean slate somewhat.
And Matt brings up a good point, but I can't see anything SW failing at the box office to the point that they'd shelve it. Even The Clone Wars did ok when it came out I think, and a lot of people were dumping on it from the gate. I thought it was good, but I'm a LFL whore at this point.