I agree the UK pavilion needs more than what it has, but with as rich and lengthy a history as those countries have, it would be a shame to sum up British history with...The Beatles. A Beatles attraction would be akin to adding a Bruce Springsteen attraction in America. He's great and as All-American as they come, but for summing up American history at EPCOT? I just don't see it.
We've yet to even see WHAT Disney is going to do with the Marvel characters, or even if they're going to have any presence in the parks. So there's no way to know what amount of adaptation or "Disney-fication" might happen.
Nothing I've suggested was intended to short-change OR dismiss Disney's talents, either past or future; I was only pointing out that Disney's history is filled with properties not wholly original, and when you start criticizing some without even recognizing all the others in the past it makes the bias stand out pretty clearly.
The Muppets, Marvel, and even Pixar get a lot of bad press because they're the most recent add-ins, but a whole lot of other characters seem to get a pass because they've been around long enough that for those young enough to have grown up with them they already seem a part of Disney.
And while that list is pretty long and constantly growing, the strong majority of these characters and properties seem to end up going directly to Hollywood Studios, and because I have enough faith that Disney knows they can't just "shoehorn" certain things into the Magic Kingdom, I don't think it's necessary to dismiss these new characters before we've even seen HOW they might be incorporated into the parks, if at all.