When does the next big celebration start? Also, when do the newest rides open up? We are thinking of April 2005, but am thinking that that is a little early for the rides and events.
I'm not sure exactly what you mean by "big celebrations," but the Disneyland anniversary in 2005 should be big (in CA, at least).
The new Stitch ride in the MK (on the site of the old ExtraTerrorestrial Encounter) opens this fall, Soaring Over California is under construction in Epcot (late 2005 opening, I think) and Expedition Everest in AK (opens 2006).