See Installation Status of All App Updates
Unfortunately, there is no feature like this built into iOS. Something may exist with a Jailbreak, but I am not aware of such a tool. 

You have something 'like' this in the Mac App Store, where the update screen shows the progress itself. 

You can possibly suggest the feature on Apple's Feedback Page, or submit a bug through Apple's Bug Reporter.

Luckily, in iOS 5, multiple apps can be downloaded and installed simultaneously, so this should speed up the process, and make it more noticeable.