Aren’t we all? you’re thinking. (No.) Fine, so Kevin Federline  is perhaps not the most current D-List celebrity that Eminem could work into his new single, but it’s okay: He name-checks the Kardashians, too. (It has not been a great week for poor Khloe.) “Berzerk,†the first single off the upcoming MMLP2, is produced by couch enthusiast Rick Rubin and will probably remind you of some other, earlier white-rapper protégés of his. We’re covering all nostalgic bases here.