Expedition Everest is opening early to some people. DVC members (and 3 up to 3 of their guests) and AP Holders (looks like AP holder only) will be able to take a ride in January from the 26th thru the 29th. So if you fall into one of those groups and will be in the World at that time, you are in luck.
Otherwise, you might get lucky in the early Spring when they start doing soft openings for the general public.
Have fun!!! If you happen to make it in January for the preview, see you there!!!