Not a good idea for Paul - since you are out shopping anyway, but....
I did, however, just discover that Goodings will deliver to the resort. So, if you are willing to pay their prices (and order $50 worth of groceries, and are willing to pay a $10 delivery fee) you can have your groceries delivered and not have to go out of your way - with a better selection than the WDW stores. Prices seemed pretty comparable to our recent Screen Door trip (eggs at Screen Door, $1.25, dozen eggs from Goodings $1.29).
We have our groceries delivered at home, so I'm not used to grocery stores - then a strange store on top of that - plus regionalism (regional brands and preferences meant we were looking in the wrong place for the wrong thing) - and our grocery stop was a nightmare. I'm trying to figure out how to avoid a grocery stop in the future - and still get some things I need. I'm willing to pay a little for the convinience - even Goodings prices are a drop in the bucket when we start talking about a Disney trip.
IIRC, one of the stores (Albertsons?) will let you fax in a list and they will shop for you - so your grocery stop is just swinging by to pick it up. Albertsons does offer delivery in some other markets (the Bay Area) so maybe delivery will come to Orlando shortly from somewhere other than the opportunistic Goodings.