Unfortunately, there have been errors and some not-so-good advice in replies to this thread.
Here's how Disney explains the inbound luggage service at
http://disneyworld.disney.go.com/planning-guides/in-depth-advice/airport-service/
Upon landing at Orlando International Airport, skip baggage claim and proceed to the Disney's Magical Express Welcome Center in the Main Terminal Building, B side, Level 1. Disney's Magical Express service will collect your luggage and deliver it directly to your Walt Disney World hotel room within 3 hours after you check in at the resort. Luggage delivery service provided by Disney's Magical Express is available for flights arriving between 5:00 am and 10:00 pm daily. For airport arrivals after 10:00 pm, Guests may collect their luggage at Baggage Claim and transport it with them on the motor coach.
Notice that is says, "within 3 hours after you check in at the resort" (
not "3-4 hours after resort check-in"). When we've been in the room, our bags have shown up within an hour of check-in. (Other times, we left the room soon after check-in, so I don't know how long it took.) It depends on how busy they are.
Notice that it says, "Disney's Magical Express is available for flights arriving between 5:00 am and 10:00 pm daily" (
not "ME doesn't deliver bags after 10 p.m.").
Although throwing away the yellow DME tags and waiting for your bags at baggage claim is an option (and a necessity for arrivals after 10 p.m.), it's usually not a desirable choice. It's not unusual to wait 30 minutes for bags at Orlando. Between that wait and the extra time trudging to and from baggage claim, it's likely you'll be on a later DME coach, so you'll arrive at your resort 30 to 60 minutes later than if you had used DME's free inbound baggage delivery. It also means tipping anyone who assists you with your bags (airport porters, DME driver, resort bell services).
If you use the DME inbound baggage service as designed, Disney covers the tips. You don't even have to be in your room.