Protools does this really well, and its one of the few features of protools I envy.
 
I know we can automate clip gain, but it doesn't get represented by the waveform. It'd be nice to be able to see how the clip gain is affecting your clip so you can make sure you're not overdoing it or need to push it further.
 
The little volume fader would be nice, but I'd be happy with simply having the automation change the waveform display to match the adjustment.