Have you tried this? SHows functions in a tag bar in vim.

http://www.vim.org/scripts/script.php?script_id=273

I think I tried that one out when I was giving Vim a whirl. Unfortunately I couldn't get into it. If there was something similar for Sublime Text 2, I would be very interested.

Command/Ctrl+R will bring up the symbol explorer in ST2. Basically the same as Coda's function explorer.

I do wish it could be a permanent fixture on the sidebar though... not sure if this is possible or not with a plugin.