It was announced today that Kanye West, Chris Rock, Chris Brown, Mary J. Blige, Jill Scott, Morris Day and The Time, and Maze Featuring Frankie Beverly will be performing at the 2008 Essence Festival.Kanye West will be fresh off of his "Glow in the Dark" tour with N.E.R.D., Rihanna, and Lupe Fiasco. While Mary J. Blige will have just concluded her tour, "Heart of the City, with Jay-Z.It was also