I’ve just created a new page in the Atlassian Developer Network called the Plugin Wishlist.
If you have a great idea for a plugin, add it to the page. Or if there is some bit of functionality you need that you think would make everyone’s else’s life easier as well, add a request.
Who knows: maybe some developer will decide to build your plugin out of a over-developed sense of generousity. Or they’ll tackle the project out of sheer boredom. Or maybe a new developer will want a good excuse to learn how to build plugins; it’s always more interesting building a real app. Or perhaps your request will spark an idea for the next Atlassian ShipIt Day.
Do your best to describe in detail what you’re after — it’ll make it more likely that you end up with something useful.
On the other hand, if you happen to have built a Jira or Confluence plugin but haven’t yet shared it with the rest of us, now’s the time. Your work is in demand — get the glory and adulation that you deserve from legions of appreciative Jira and Confluence users. The world is waiting.

All I want for Christmas is a new Plugin...