Well why not throw on yet another rumour. The Motu Proprio, of course, has moved well beyond mere speculative rumour, that much should be a fact.
One can never be certain whether rumours come from legitimate sources, of if rather it is an attempt at a "self-fulfilling prophecy" -- create a rumour in hopes of having it come to pass.
Still, with our Holy Father, one never knows with these liturgical initiatives, knowing well his sensitivity to it and the cultural war which Christianity faces.
Another rumour coming from the rumour mill comes from the Times Online, Pope to throw open the 'Flaminian Gate' to Anglicans which speculates about some kind of corporate solution for "traditionalist Anglicans" disaffected with the continuing liberalization of Anglican practice and doctrine.
Personally, I should think that it might be more likely for the Pope to seek the expansion of the existing "pastoral provision" Anglican use as is in effect in the United States.