I've got an Apple ID problem, too. All of the sudden in the midnight between August 31st and September 1st, the new apps I picked up on the App Store hung forever 'Waiting..' in my iPhone and never turned 'Loading'. When a substantial amont of time had passed, they reported, they 'could not connect to the App Store' and .. disappeared! Well what they told was not perfectly true because I could however connect to the store as I could browse and pick the apps, but the apps just didn't load. I tried to log into my account in iTunes on my Windows 7 laptop, too, and there got exactly the message in the topic title.
It appeared later my Apple ID did not completely fail because when I switched from my home WiFi to the phone 3G, everything worked just as nothing happened. Logically, this intimated my WiFi had flaws. Or, some place between my WiFi router and Apple servers did, to be precise. My router was not to blame because I did no changes to it whatsoever.
All right, it is Saturday today and my ISP is running in unmanned mode meaning no hotline, but I call them on Monday unless the problem disappears by itself. I just wonder what I say, because from non-i-world point of view everything works well, and I know for sure guys in the ISP support don't own any i-stuff, (because they are all android fanatics) . I'm not telling them my Apple ID to let them reproduce the problem on their home equipment, which means I come almost totally proofless.