I just spent 4 weeks in WDW with my laptop (and a week in
Disneyland prior to that). I stayed at the Pop Century, All-Stars Music, Grand Floridian, Fort Wilderness Cabins, Saratoga Springs Resort, and the Animal Kingdom Lodge.
I own a laptop cable lock (a combination one) and used it in each of the resorts that I stayed in. My concern was not about Housekeeping but rather about the scam artists that can talk their way into anyone's room. If someone was going to sweet-talk their way into my room, I wasn't going to make it easy for them to five-finger my laptop out of there.
I should also note that with so much resort-hopping going on, there were times when my resort room wasn't ready upon check-in. During those times I checked my laptop with the Bell Services folks and asked them to make sure that it was locked up in a secure place. They assured me that it would be, and it was, because nothing disappeared from my laptop case (amongst other things, I had an 80 Gig external hard-drive in there that could have very easily disappeared).
I am glad that I brought my laptop with me on my WDW vacation. That was the first time that I ever did that, but since it was an extensive trip with just me and my children, I promised my husband that I would send him photos & videos of our antics. Having my laptop with me was the only way that I could do that.