After iPad (first generation) iOS 4.3 update, the App Store displays wrong release dates for updated applications, as can be seen in the captured image:
Wrong date: 29 October 2009, although the application update was released on 16 March 2011.
The App Store shows correct update date on my iPhone also running iOS 4.3:
Update: The issue is still not fixed in iOS 4.3.1, at least on my iPad.
Update 2: Issue still present in iOS 4.3.2
Update 3: Issue still present in iOS 4.3.3
Update 4: Issue still present on my iPad 2 in iOS 4.3.4, appears to be fixed on iPhone 4 iOS 4.3.4
Update 5: Issue still present on my iPad 2 in iOS 4.3.5
Update 6: Issue still present on my iPad 2 in iOS 5.0