This got me thinking; what countries would you most like to see presented at World Showcase? Also, if you like, give reasons.
Ireland: As it's nextdoor to the UK, I've been over to Ireland quite a bit and it is lovely, and would make a nice addition to World Showcase. My only qualms with this as a possible addition is that it may end up looking too much like the UK pavilion or it may go down the shamrocks and merry drunks route, disregarding the Celtic flair. They could possibly base the main area on an Irish village (possibly a fishing/seaside village due to World Showcase being formed round a lake?) with an attraction/show based on Irish legends with a small Irish pub-cum-restaurant.
Sweden: This could form part of World Showcase easily as well due to the Lake. Stockholm is interwoven by waterways, and the buildings there are pretty, so a replica could slot in well. Plus, they could open an Ikea in Epcot!
India: I know that there's the Asia area at the Animal Kingdom, which has a number of nods to India in there (what else do you think of with a place featuring an attraction based on Maharajah Jungle Trek? Lithuania?). Needless to say, it would be lovely to see an ode to the architechture of the country.
Finland: This could be a charming area, with traditional Finnish buildings like this and this. Okay, the latter is actually a replica of the Moomin characters' house, but it still has a cool Finnish feel to it. And at Christmas, there could be a Santa's Grotto open (the original legend was that Father Christmas actually lived in the Finnish area of Lapland, not the North Pole).
Estonia: The old town area of its capital, Tallinn is so lovely, that it could inspire a whole theme park, let alone an area of one. Therefore, I nominate Estonia as a possible candidate for a pavilion.
Spain:
I know that they declined to support Disney's version of Spain, yet I just love the raw feeling of traditional Spanish things. Plus, they could add some cool Gaudi-esque stuff.

And now, for countries that I wouldn't want replicating (I'm not implying that I have any hatred of the countries on the whole):
Israel:
I know that they declined sponsorship, but even if they didn't, I can't really think of anything iconic aside from stone buildings and anything religion related. If Disney went along the stone building route, it may look a bit dull and pointless and if they did go along the potentially more interesting religion route, I'd simply find it a bit tacky.
Belgium:
Places such as Bruges in Belgium look like great material for World Showcase, but I must admit that a Belgium Pavilion may end up a bit too similar to the French one, therefore making it seem a bit needless.