The thing about irony is that its timing is always impeccable. Last night I got the new issue of Rolling Stone, which had a front of the book article on "Inside Michael Jackson's Troubled London Comeback" about the performances scheduled to happen next month. Before the singer's unexpected death yesterday, though, there was already concern over whether the King of Pop would make his dates. According to writer Fred Goodman, concert promoter AEG Live (which locally books the Warfield and Regency B