The most interesting thing for me is that Christine added lyrics to instrumentals Lindsey did with Mick and John. I didn't know that. I was worried half of the material would be Buckingham and the other half Buckingham-McVie which would have resulted in a lop-sided album. If, however, she's given lyrics to his music and he's added music to her lyrics then it really is a proper, full-on collaboration.
Hmmm, I wonder if they'll be naked on the album cover