It's so crazy you can't help but be intrigued. I've never heard the music of James McCartney or Dhani Harrison before. Sean Lennon I think is a bore (Julian sounds more like the good bits of his dad's music to me).
Of the whole bunch, Zak Starkey is the most impressive musician. He's a phenomenal drummer -- the best fill-in for Keith Moon that The Who ever had, among other things! But he seems very "willful and independent" (The Who offered to make him permanent drummer, but he turned them down. Can you imagine?? He must be a very confident lad!) So I can't see him doing it. (The article notes they may recruit Jason Starkey to play drums -- who's that? Sheesh!)