Sadly, I don't see a change coming any time soon. Nestle is a major sponsor, as already noted.
I did discover that the Big River Grille serves Seattle's Best brewed coffee, which is a much better option. You could also try the three non-Disney run coffee bars around Epcot (between UK and Canada; on the walkway before Mission:Space; on the walkway before Mexico). I don't know what type of coffee they serve there.
The Starwood hotels (Swan/Dolphin) are 'proudly brew' locations ie they serve Starbucks brewed coffee (but do not have a Starbucks on site)
The espresso drinks vary widely. For instance, the beverages at the crepe stand outside France used to be excellent, until the machine broke last year and didn't produce well. The espresso drinks inside the bakery are horrible flavoured beverages from the machine.
My personal preference remains the espresso stand in Italy, but it may take some trial and error to find your preference.
In addition, it is frustrating to discover how often Disney's espresso machines break. Earlier this year I encountered broken machines at POR, the new Land food court, BCV, and BWV all in one day! I finally discussed this with a manager who agreed that the machines simply cannot handle the high volume required.
That's why I stick with my own coffee and mug!