If you're an international user who just picked up an iPad in the US and want to get some apps via the on-device App Store app, you 're out of luck: "Cannot Connect to the App Store. The App Store is not supported in your country"
That's what you'll get if you synced via iTunes on your Windows PC or Mac using an international account, like Canada, Australia, UK, etc. and then try to use the iPad App Store app.
Of course, you can just keep on syncing via iTunes but for the convenience of the on-device downloads, you'll need a work-around.
And boom, the App Store app will start working. Now the bad news: anything you download will be locked to your new US account, which makes managements more of a hassle. And if you want to buy apps, you'll need a US credit card or US iTunes gift cards. But if you gotta have it now, that's the only solution we have working (if you know a better one, drop it in comments!)
Hopefully before the iPad launches in more countries in "late April" Apple will sort out this little problem and we'll all have on-device App Store access no matter what country we're in...