Thats some good advice you got there Robert! I think it speaks volume of the difference between WDW (mostly indoor rides) to DL (mostly outdoor rides).
A tip, which I will put on the top tips is I think the best WDW park to go to if you know its going to be pouring the entire day is EPCOT. Most of it is indoors!
The rain here is miserable, but the Cali/Florida rain is warm and inviting.