Last fall Diesel celebrated its 30th birthday in Brooklyn with a concert by N.E.R.D., Franz Ferdinand, T.I., and a very pregnant M.I.A. So expectations for last night's Diesel:U:Music event and its promise of very special guests were high (like planes) (sorry). Jay-Z would probably show up and spit with the Roots? He is in town! Hipsters adore him! But Jay-Z ...