Some clips are very hard to see and hear and they wont show up on typical waveform display. To be able to switch project window to display all events in spectrogram mode, or, switch individual events to spectrogram view.
This is actually a great marketing strategy because it will help Steinberg sell Wavelab to get spectrogram editing tools.
+1
I would just like to point out that Samplitude pro has had this for sometime
I think it would also be smart, that if someone does have Wavelab, that the Spectrogram editing tools also become available in Cubase. ie, If you already have Wavelab installed, or you have Cubase and then install Wavelab - there is some cross integration in terms of features and tools.
Also smart marketing, it consolidates a lot of tasks into using just one program instead of having to switch between both, and or, having to use a non-steinberg software.