Back in 2009, my parents took the whole family to WDW for their anniversary. For about the first 2 1/2 days...it rained. I don't mean the afternoon passing shower. It rained! Downpours. We were disappointed at first. But then realized we have to play the hand we're dealt. We all had ponchos, and wrapped our son's stroller in a couple different ponchos to keep him dry as well. Our feet got wet, and the kids actually enjoyed getting wet. But once we just accepted it, it was fantastic! Light crowds. Short lines. Not too many attractions closed in the rain. So we actually had a great time! Our last few days the weather turned out great. So just embrace it and go with the flow! If you don't let it slow you down, I'm guessing you'll still have a blast. Have fun!