Actually, I did this once (the one and only time I received a PIN code). This was for October 05.
We were arriving like on a Wednesday and friends were coming in Friday. When I was trying to book initially thru disney (the 800#) - room only - was told it could not be done. Despite the fact that I could reserve up to three rooms, they said all had to check in same day and of course, I'd have to be present at check in for all.
Hung up and tried dialing CRO again (as we all know we get different answers from different agents). I called back on my cell the second time on their regular 407# and before I got much into the conversation, the land line rang. It was the first agent who said it couldn't be done calling me back to tell me yes, they could do it!
What a nice thing for the agent to check after I hung up and call me back!
So yes, it's been done. Whether you'll get an agent who do it is always questionable.