I suspect it is two separate issues:
USD is by far the worse because no matter where or to whom it is going a USD wire will be routed through a US Bank, and MTGox has had some serious problems with the US Government.
Other currencies is more a question of getting additional banking partners, and addressing the serious load that the number of wires they send is having on their banking partners.
If Mt. Gox had "serious problems with the US Government", there would be press releases from DOJ or the SEC, news coverage, and possibly arrests. They have serious problems with CoinLab, which is suing them for good reasons. They might have serious problems with some Tokyo banks. But even that is unlikely. If you have money, you can generally send it somewhere else. If you don't...
Mt. Gox had trouble at the US end, they'd probably be blocked from
receiving money transfers. They're not. Somehow, the only things that don't work are things that take money
away from Mt. Gox. That's very convenient for Mt. Gox.