You never know. If memory serves, wasn't a Zelda being developed for the Wii a year prior to TP's release? Someone correct me if I'm wrong, but that's what I remember hearing. Anyways, it's certainly a possibility, if that's the case, that a new Zelda may be coming out sooner than we think.

However, I'm sure that development was not entirely consistent throughout, due to the decision halfway through the development of Twilight Princess to port it to the Wii as a launch title, et cetera.