According to D&B "polyvinyl-coated cotton fabric is generally water repellent and should repel most soil"
So theoretically carrying it in rainy weather shouldn't be a problem.
I was more concerned with the light colored vacchetta leather darkening unevenly if it has gotten wet, but now that I think about it, I bet the oils from your skin are worse where that's concerned than rainy weather, and you can't avoid touching it, so what are you gonna do?
Honestly I think the Disney Dooney's would be fine in in rainy weather, but I admit I have no first hand experience because I tend to play it safe, leave my nicer handbags home, and just use my LeSportsac bag if the weather is bad. We don't normally have many rainy days where I live though.
Wendy,
We got in a bit of trouble for offering to buy, sell, trade here. But that's all allowed on the facebook page. I think it's been pretty quiet over there lately, but you might want to check there. I can't help with WDW bags, but I picked up DL bags for several folks at cost. I bet there are Florida folks who would do the same with the WDW bags.
http://www.facebook.com/update_security_info.php?wizard=1#!/group.php?gid=144858772203757