Rocker Slash's upcoming solo album is promising to be a star-studded affair - he has added Velvet Revolver bandmate Duff Mckagan and Dave Grohl to the list of big name guests. The untitled release will also feature Nine Inch Nails star Josh Freese, ex-Jane's Addiction rocker Chris Chaney, Ozzy Osbourne, Red Hot Chili Peppers star Flea, Iggy Pop, Fergie and Chris Cornell.