Spectrogram waveform display

It would be really cool to have a spectrogram (like this: http://www.freesound.org/data/displays/185/185770_3113541_spec_L.jpg ) as an option for the waveform view. Ideally one for each channel (with low frequencies in the middle, high at the top and bottom).

Pros:
- HEAPS more tone information.
- Would look pretty cool.

Cons
- It's pretty CPU intensive, depending on window size, and band widths.
- Probably less precise at finer scales (might be a problem for fine-tuning beatgrids).

I don't really know how practical this is, but I thought I'd throw it in as an idea, anyway :)