Coffee at WDW:
The grounds you buy in the stores are unidentified. They aren't bad, but are roasted a little dark for my taste with no selection (regular and decaf - both French Roast - at least that was all that was available in October 2005 at the Screen Door).
Most brewed coffee is Nescafe from concentrate - for someone who gets their morning cup from the independantly owned coffee shop and finds Starbucks beans to be "not high enough quality" - it utter swill. For someone who drinks cheap foodservice coffee by the pot from the industrial drip from work, its fine. There are some exceptions (Kona Cafe). (And the great restaurants at Disney will never be really great until they serve a good cup of coffee).
The tap water is sulfurous....slightly to some tastes, horribly to others. Water is a very important ingrediant in coffee and sulfurous water will throw off the taste.
If you are a severe coffee snob, bring your own beans and grinder (Peaberry for us please), bottled water and a press pot. If you will drink the public food service for free coffee at work (which tastes like old gym socks to me), don't worry about it. For anyone in the middle, decide what level of coffee control you need and go for it (we don't bother with the press pot, the cheap drip coffee makers they have - while I wouldn't own one at home - are fine for vacation. The sulfur water doesn't bug me - I live in St. Paul so mine tastes vaguely of fish several months a year - sulfur is an improvement - and we brew ours strong enough that we don't taste the sulfur. We don't bother with a grinder, the slightly stale quality of beans ground a week ago doesn't create the best coffee in the world, but we cope. But we do bring our own beans.)