although i don't know what Ivan will bring, currently the roads around WDW, the airport, I'drive, etc are all fine... very minimal visible damage (i.e. trees down) although lots of blue tarps on homes lining the streets
as far as food goes... everything is status quo... we were strongly encouraged to keep some provisions in our rooms (i.e. cereal, pbj sandwiches, fruit, veggies, snacks, etc plus water/soda) in the event we had to be confined to quarters (if the winds were too strong to safely walk around outside)
as for water... we don't care for local water (other than our own) so stuck mostly to bottled but the local water we did drink (i.e. in restaurants) yesterday and monday was fine! not scarce at all... our only concern for scarcity was gasoline, but that proved to be a non-problem in the wdw area as well...
personally, i would still keep my plans... having lived thru frances at pop century, i was more than impressed w/disney's ability to handle a bad situation with grace... keeping their guests safe, entertained and happy! we were given up to date info, encouraged to have food/water in our rooms, offered coolers to store provisions in and given bags of ice (when the ice machines ran low) gratis...
in the lobby area the children had the opportunity to hang out w/minnie, mickey, goofy, pluto, pooh and tigger all day and night (saturday and sunday!) as well as offered games (bowling, beach ball volleyball, hula hoops) and arts and crafts... the mousekeepers even made an appearance offering lessons in "how to create towel animals" that seemed to be a big hit with many many people!