I just release GitGutter, a Sublime Text 2 plugin to see line changes since the last git commit in the gutter.
Wow, cool! Didn't know ST2 plugins can do that. Can I manually invoke the diff view?
Well, thats not really built into it, but as long as it as been invoked once before (meaning its in the collection of views it is keeping track of) you can type "ctrl+`" to open the console and run:
Although I may add that as a feature in the future. Glad you like it.