I really question whether a second Pasadena Rose Bowl night is even intended. There is room to add it on the 26th, but in 1997, they eventually sold around 65,000 tickets for the Coliseum and the planned second night there never happened. The Rose Bowl will be able to hold around 90,000 for U2, so while I think that show can sell out, I'm not really sure that a second show would sell well enough to justify 2 dates. In 1997, Philadelphia sold out and they added the second show, but it sold real slowly, reportedly only around 10,000 tickets sold before they cancelled it and replaced it with a performance at the Tibetan Freedom Concert on that same day. By being held on the same day, it gave them an excuse as to why they cancelled Philadelphia night 2 instead of stating the poor sales as the reason.
They may be thinking to give the L.A. area a second show in June-July 2010 instead. I picture that Chicago, Foxboro, East Rutherford-New York area and Pasadena-Los Angeles area are cities that may be getting shows on both legs. Toronto could maybe also get a 2010 show.