Shift-cmd-T was just a quick proof-of-concept (using the language grammars to capture symbols). It'll probably be more like cmd-T but move to the status bar (as a popup) -- it's one of the things on the 1.1 shortlist, but it's also one of those things I just really don't get why people need… ;)
Don't ask, just do! No seriously, I have this js file with a class and it has LOTS of functions, like get/set stuff mostly ... and it's good to be able to navigate around that. I probably should have it all documented more properly, but this is a spare time project so I don't really feel like documenting to much, and then the symbol navigation thingie comes in handy for asking questions like "was it setHomeXY or was it just setXY, and what is the difference ..."
Andreas