The reason for not playing in South America in January 2002 (as originally planned) was mainly a money issue. Due to the decreasing value of the currency against the dollar or the Euro, it makes it hard for them to go there. For Popmart in 1998, for the only time ever, U2 accepted tour sponsorship from a company to help with the costs of bring that tour to South America and Paul MacGuiness later stated that U2 did well on the 1997 portion of Popmart but lost money on all the 1998 portion.
A potentially good sign for South America this time is the fact that the Rolling Stones are planning to take their tour to South America in early 2006. The Stones are also promoted by the same company that promotes U2's tours, TNA. If TNA has found a way with South American promoters to allow the Stones to tour there and not lose money, then maybe they can convince U2 that they can do the same for them. Also, Bono stated when he received the Pablo Neruda award last fall in Dublin that he hopes they can get back to South America on this tour, but then again, in November 2000 on Globo TV in Rio De Janeiro, he stated that U2 would come to Brasil for Elevation and that never happened.
I really hope it happens for all the great U2 fans in South America. They really deserve it after how great they made U2 feel on the Popmart tour. I wish Paul MacGuinnes would think that even if U2 lost money on taking the tour there, that they would end up selling a lot more cds to excited fans. Ths is a lot of extra money that U2 may not otherwise earn in South America.