@Sanjay Samani: The timeline could also work line iPhoto's shelf in edit mode, as an easy way to pick two older versions to compare, compared to the clunky interfaces we have now
There actually is a feature like this in Versions to compare two separate revisions (based on what I think you're describing), but it's not exactly a shelf. I'm not sure if that would work well with textual content, but maybe I'm missing your point.
Be able to select a line(s) of code and find out quickly when & why the were added.
There is something similar to this in Versions, but I'm not sure if it works exactly as you describe it.
by Scott Stevenson — Jun 01
There actually is a feature like this in Versions to compare two separate revisions (based on what I think you're describing), but it's not exactly a shelf. I'm not sure if that would work well with textual content, but maybe I'm missing your point.
Be able to select a line(s) of code and find out quickly when & why the were added.
There is something similar to this in Versions, but I'm not sure if it works exactly as you describe it.
A lot of great ideas, though.