It's a question of picking your battles, really. The US market is huge, yes, and that makes it important to any international corporation. But when you're releasing product to remain competitive in the rest of the world (because you're getting beaten over the head by Amazon and Barnes & Noble in the US) and you don't have a strong retail partnership until 2013... what's the better move? Focusing on the market where you have difficulties you know aren't going to get resolved in a timely manner for your product launch, or focus on the markets where you're trying to maintain your competitive advantage?
There are pluses & minuses to any approach here.