We have never used ME and don't plan to. We have a pretty good relationship with a limo driver that we use every trip. It's really so nice seeing him standing there with that sign with our name on it. He helps us get our checked bags off and has a luggage cart waiting.
I guess the only thing that will effect us is that we will put all lotions, gels, etc. in one of our checked bags. We ALWAYS have several checked bags. DH and I do take the small easy to wheel suitcases on the plane with us, but they just have our clothes. We may even check them this trip. We each carry the small bag that goes with our luggage sets and we put cell phones, tickets, any medicine, my make-up...stuff like that. I guess some of that will have to go in checked bags now-not a big deal. Each of my kids has a back-pack with stuff for them to do on the plane-books, game boys, ipods. I'm not sure if we can still take eletronic devices on-we will check before we go. My sons may have to *gasp* read the entire 2 1/2 hour flight.
We usually check 3 large suitcases. The two real big ones with our luggage sets and another large one. I don't know how people travel with 3 kids without checking bags! The first time we went to Disney with our youngest DD she was under 2 and we had 7 or 8 checked bags, a stroller, and a bunch of carry-ons. When the limo pulled up at the BC, the bell-hop had to get 2 luggage carts-thank God our room was ready!
We arrive early, try to check-in, and then go straight to an early lunch at ESPN (my DS's favorite). After lunch we go into Epcot for the rest of the day. So, we don't need bathing suits. I suppose if we need sunscreen (I have never gone in Oct-only Dec and March-Oct may be hotter/sunnier

) we can always buy at on the boardwalk or in Epcot. I know we will have our checked bags with us, but I wouldn't want to waste time digging through them for sunscreen while the bellhop was waiting to store them.
One of my neighbors is leaving for Disney next week and she said she plans to sunscreen her kids at the airport before security screening and then throw it out. She plans to just buy new sunscreen when she gets to the POLY. I told her I think her kids would be fine with out sunscreen until then, but she is a little bit fanatic about it! Plus, we are only like an hour from the airport...I don't see why she can't do it at home! I think people panic too much about these things.
I think Crisi's idea of sending a box UPS or FEDEX there is a good idea for people worried about ME. I also think she's right about how fast the luggage comes out. I'm sure you could grab your smaller bags and take them on ME with you.