I think NASA has some of the best points in this thread. The wand does not belong at Epcot, or at least shouldn't belong in the OLD Epcot. The old Epcot (at least in Future World) focused on science and the study of nature and the world around us. In Disney's (and every other major corporation's) need for synergy they tried to incorporate aspects of all their products into all their properties...thus a Mickey hand and wand over Epcot, and the re-branding of The Living Seas (which, while I actually find really cool and entertaining, has lost a little bit of its educational approach).
Mickey doesn't BELONG in Epcot. The Magic Kingdom is his realm and that's where he should stay. A stronger argument can be made for the hat being in MGM than the wand being in Epcot. The hat ties into the movie Fantasia, Walt's masterpiece. MGM is also the only park where Mickey is available for meet and greets in his Fantasia costume.
But Epcot? Where does Mickey fit in? We see him in the topiaries, and in the merchandise. But other than that, he's only seen in the hidden mickeys around the park, and that's the way it's meant to be. Subtle ties to the fantasy world of Magic Kingdom are fine at Epcot. There should be a little "magic" in the park. But most of the "magic" should come from observing the little magic and wonders that occur in the world around us. That's what Epcot's all about. It shouldn't be blatantly proclaimed from the top of Spaceship Earth.
Epcot has certainly changed over the years, even before it was built. But it was never intended to be another Magic Kingdom. The wand isn't just a departure in design, it's a departure from the original idea of Epcot! wdwmagic mentioned earlier in this thread that "The wand is appropriate because like it or not, Epcot IS a Disney park. Ultimately, without Mickey Mouse, Epcot would not be there. Why shouldnt there be some recognition that Epcot was born out of Disney?" When Walt did his live TV spots about nature, and when he was having talks with his TV viewers while tigers sat on his desk, Tink wasn't flying around sprucing up the action. When his idea for the Jungle Cruise came about it wasn't focused on his animated characters getting into an escapade on the river. It's about real life (though the Jungle Cruise takes a little bit of a fantasy dip; but then again, it's in the MK).
Epcot doesn't have to appeal to a wider audience to survive. <a href="http://www.coastergrotto.com/theme-park-attendance.jsp">Epcot was the third most visited in the US in 2005</a>, and when the first official TEA/ERA Amusement Park Attendance Report comes out in April I'm sure it will still be near the top.
The only thing at this point that's hurting Epcot is becoming obsolete. The way to fix that is not to inject superficial "magic" into the park. Get back to the roots of what the park is supposed to be about and enhance those sections. When's the last time Universe of Energy was updated (or widely attended)? When is Journey going to get it's groove back? Is Body Wars ever going to open back up (and does anybody really want it to)? Epcot's got a lot of problems, but the solutions that have been put forth lately seem to detract from the park's message, not help it.
Just my opinion.