I would find it helpful to have an extra query similar to 'g' ("Find this function definition") that went to an object's _declaration_, if it exists (rather than definition).
One project I work on has a documentation style where full function documentation is kept alongside the function's declaration (generally in a header file), and only perfunctory if any documentation near the function's definition. With cscope as it stands, this documentation is hard to get to -- I have to do a 's' ("Find this C symbol") query and pick out the declaration from the potentially many other references.
I have no idea how feasible this is with cscope in its current shape, but it doesn't sound as doomed as some of the other feature requests here ;)
Neither 'g' nor "find this function definition" actually exists in (this branch of) cscope, so I'm unsure what you're getting at.
Sorry, I meant "Find this global definition". (The single-letter command 'g' comes from my Vim keybindings for cscope, so wasn't a useful referent either, sorry.)