haha rocks not dead, it's different. sometime in the 80s the record labels stopped being run by music people (like the 60s and 70s) and through the 90s and 2000s the selling points of records have been everything other than music. its more marketing and making the acts commercial and such. plus the radio plays rihanna or eminem or whatever way more then they'll play the latest rock singles. but no one uses radio anyway.
This is the year 2000 all over again. I remember MTV had this big special that featured members of Korn and Limp Bizkit, various pop artists etc talking about rock being a dying genre. Then all of a sudden some of the biggest acts in the mid 2000s were rock bands (Nickleback, Puddle of Mudd, System of a Down, Jet, Hinder, Creed, White Stripes, Shinedown, Red Hot Chili Peppers, etc etc). Obviously not GREAT rock bands all the time, but they were huge during that period of time and some still are pretty big.
It's cyclical. Great artists come out and carry a genre. Rock will have it's day again, and I honestly can't say that it's entirely declining anyway.