Add me to the list. It just started happening a day ago. Red icon claiming updates needed on my iPad App Store icon.
Attempted the suggested solutions mentioned above and still have the red alert for updates on App Store icon. Updates "tab" on App Store app is still completely blank.
I also tried a hard reset, deleting history and cookies on Safari, and even tried deleting my iPad iCloud backup and tried to back it up again. I also tried resetting my sync history, reset warnings, and cleared the iTunes store cache.
I am on Windows 7 X64 SP1, iPad 4th Generation 64GB Wi-Fi model on iOS 6.1.3., iTunes 11.0.4.4.
Also, on a strange note that has started happening recently (makes me wonder if the so-called "harmless" hacker that took down the Apple Dev site didn't bury some sort of malicious code or virus that spread to the entire network) that on iTunes under where the apps tab, I keep getting random icons that show up as either black, or some sort of garbled mess instead of the actual app icon for it. I get the same thing on my iPad under when i sync/update apps. GIven just how long it has been the Dev site has been down, it really makes me wonder just how "harmless" that hacker was.