The answer is YES. I am going in September, and I called last week with several planning questions. Among them was this question. I was told by an extremely pleaseant person (Nicolette), at WDW that you could ship a package ahead to your hotel. She advised that it should't arrive too soon before your arrival (3 or 4 days would be OK, but not 2 weeks), and that it should clearly be marked with:
Please hold for (Insert name of Guest used for Reservation).
Arrival date is: _____-_____-_______.
It is apparantly very important that that information is on the package (Name, and arrival date), so that it can be held in the proper location, and be ready when you get there.
You should also call your hotel to get the exact mailing address of your hotel, instead of just "Walt Disney World"....I can imagine they get a bunch of mail/packages a day, and it may take quite a while to sort it all.
Good Luck