"I can't see them holding anything back until the day before the AGM. If they had blockbuster news they would have released this at time when it would influence the vote in thier favour."

Certainly possible, though we haven't received that which we were lead to believe would be coming and for the few announcements which were received with sp repression what would have been the point to reveal the big news? The big news, though perhaps not likely, could be used for fence sitters and those voting at the AGM. A mammoth announcement at the highest point of excitement might shake something lose. Purely speculation and whimsy on my part.