Apparently, it's not happening. Just read about it at u2page.com. Only one show is to be scheduled at Phoenix Park per year, and U2 are nowhere in the plans for next year. I don't know who starts these things. But just don't believe anything until it's officially announced.
My guess is that security guard at the Stones show would be more right. Tour begining in May in North American and September in Europe with arenas, and then going into stadiums in 2005 if all goes well. Joe O'hearily said something along these lines too. I'd put money on that before I'd put money on a stadium tour next year.