Long awaited release of the PMDG B747-8 has occurred, reported via their Facebook page. For more info on the product check out the source link.
Note : This is an expansion pack you will need to own PMDG 747-400 Queen of the Skies II for it to work.
Note : there has already been an update posted regarding the installer for FSX.
If you bought from today then you can ignore the update.
Source : PMDG Site