Wow, I haven't read Spider-Man, or any comics, since the whole clone saga.
I don't actually like it much, but I think stuff like this needs to be done once in a while to keep the stories and the character fresh.
I see costume changes sort of like uniform changes on sports teams. Not long after the switch, the old, retro uniforms become hot again. I believe this is especially the case with the bigger name heroes -- Spider-Man and Superman. They might change costumes for a while, but eventually they will back to their classic garbs.