A recent update to the PMDG Operations Center contains “Preparations for release of the 747-400 Queen of the Skies II.” FSElite was able to verify this on FSX, FSX-SE, and P3D.
In addition to this
the store page for the addon has been up for some time now; Claiming the aircraft is available for the low price of two hundred twenty eight million dollars. PMDG has been know to use these unbelievably high prices as a place holder for the actual price. In the past this is usually indicative of the product soon releasing. While no release date has been announced, it seems the aircraft may be out soon for all to enjoy.