This movie will performer really well worldwide. The biggest foreign markets seem to be China, UK, Russia, Germany, Australia, France, Brazil, Mexico, South Korea, Spain, Japan, Italy... Thor: The Dark World managed to gather this much in some of those markets.
China - 55M
Russia - 35M
UK - 31M
Brazil - 27M
Mexico - 23M
France - 22M
South Korea - 21M
Germany - 20M
Australia - 20M
...
I have a strong belief that TR is gonna easily surpass all of those results. The movie already looks way better than TDW just with one awesome Teaser Trailer. It looks like an insane, action packed, funny adventure in the cosmos with 2 of the biggest Marvel heavy hitters, Thor & Hulk... This is no ordinary Thor movie. Cate Blanchett as Hela looks epic. She is undoubtedly one of the things that blew more people away... The movie has the best cast ever for a Marvel movie and a very talented director.
Taking all of this into account i think the 438M total foreign gross for T:TDW is gonna be crushed and left in the dust. I just don't see this movie making less than 500M overseas.
If marketed properly and heavily in China it will already get a massive bump, the focus over there should be Thor vs Hulk with Hela a strong female villain as the looming threat and with all the action... It's sure to make people exicted over there and South Korea should follow suit. It's gonna crush in Australia with Chris Hemsworth, Cate Blanchett in the forefront and the movie being filmed over there and also with Taika, Karl Urban... from NZ, it should also help.
The hype in Brazil is already massive from what i read and watch everywhere and it's a strong market for Thor so adding everything else will just push it over the edge. It also should do very well in Europe. In Russia i have no ideia how it will perform but T:TDW had a great haul over there.