It is difficult for US customers. The problems were created by the US government in the first place (no more redeemable codes for fiat, no more LR, no more Dwolla, etc), so please complain to your government/congressman/president/neighbour. MtGox have very limited options to transfer USD, and have to be very careful not to abuse their options because abuse may interfere with their application to become a payment service. It is possible to make a express manual withdrawal for a 5% bank fee (very limited, available at MtGox's discression), or just wait it out. Trade while you wait, and you may make more USD to withdraw when it is back to normal.
I made a withdraw request with every intention of doing just this since when I made it two months ago it was already clear that there were problems in this area and there was every possibility that Mt. Gox would fail to get me my money.
Unfortunately trying to address the underlying fundamental problem (corp/gov interference) requires at least a tiny bit of cooperation from Mt. Gox. When I made an effort to obtain any usable information from them I got back standard boilerplate and nothing which was either usable or even honest. I got back the standard 'several weeks' bullshit which is both amusing and offensive.
This is actually a bit of a shame because I happen to have the good fortune to be represented by lawmakers who have taken a leading role in addressing the abusive practices of the banking system over the years, and who is especially responsive to the problems of his constituency in the case of my house representative.
edit: spelling