Hi Yetkin.
Are you looking for a place to suggest an idea that someone else could make (or check if someone already requested it)? or for lists of existing suggestions from other people that you could work on implementing yourself?
Some other wikis maintain lists in various locations, depending on the scale/scope of the idea (e.g. gadget/userscript request pages).
Generally: There are always more good ideas than there are people available to implement them, so there's never been a simple way to go about it.