Recently however, it was announced by NME that two of the songs on the album would be duets Mercury did with King of Pop Michael Jackson back in the early to mid 80's. The songs are apparently just demos because unfortunately the collaboration never came to fruition.
The first song State of Shock was eventually redone by Jackson and Rolling Stones vocalist Mick Jagger for The Jacksons 1982 album Victory. Mercury on the other hand did his own version of the other song There Must Be More to Life Than This for his 1985 solo album Mr. Bad Guy.
These two songs are no secret to fans of both Mercury and Jackson, though. MP3's of the collaborations have been floating around the internet for years and anyone tech savvy enough has in some way or another managed to get a hold of them. I have heard them both and find them pretty good. There Must Be More to Life Than This is a true gem and it's a shame it never went anywhere till now.
The album will be called Queen Forever and it will be the band's second posthumous project using vocal recordings from Mercury since their 1995 release Made in Heaven. Guitarist Brian May has also stated that the possibility exists that brand new material featuring current touring vocalist Adam Lambert may also be featured on the record, but nothing is for certain yet. I personally hope it's true because Queen with Lambert was absolutely phenomenal in concert.
YouTube links to both songs are below:
There Must Be More to Life Than This
State of Shock