It seems that a Doctor Who attraction at Epcot would be a very logical addition as the competition for european tourists escalates. Right now thousands of UK tourists are heading to Florida to visit... WWOHP. Like Potter, DW is a well-loved (particularly by the Brits themselves) British export that would attract those wandering tourists back to Epcot... maybe even make it a must-see for UK tourists. After all, the first place/park a tourist visits is where they tend to spend the most money on souvenirs and the like.
And of course, Doctor Who is catching on here in the States as well: it's come a long way from airing on saturday afternoons on PBS in 1984! DW was on the cover of Entertainment Weekly a few weeks ago, albeit as the poster child for "cult TV," it was still the cover of a national US magazine.
In addition, it would be a nice addition to one of the pavilions that doesn't have a lot attraction-wise beyond the (British Invasion/Airwaves) live shows in the garden.