The last two years, a new Rebel body has been announced in early February. Perhaps Canon had planned to follow that pattern this year, too. Then, it became apparent that the D800 would be announced at that time. Granted, they're aimed at different markets, but given the apparent pent up desire for a 5DII replacement, what would the news media have done? Could have been a field day - "Nikon gives us a 36 MP FF monster with the highest resolution FF sensor ever, and in response, Canon gives us...a new Rebel with the same tired, old 18 MP APS-C sensor."
Perhaps the T4i/650D is ready, and Canon is just waiting for the D800 announcement to fade a bit.