In a 2002 interview, when Jackson was asked if he would ever work with Jones again he replied, "The door is always open". However, in 2007, when NME.COM asked Jones a similar question, he said "Man please, We already did that. I have talked to him about working with him again but I've got too much to do. I've got 900 products, I'm 74 years old."
http://en.wikipedia.org/wiki/Quincy_Jones#Work_with_Michael_Jackson