Tried to find the similar topic, but failed :D.
While badges feature is on its way with all great stuff, what about having the some badges category, (restricted by certain categories or not) that can be awarded by the users?
Imagine the category “Custom ROM” or “SSD” or whatever, that involves lots of Q&A and support on some forums. There always will be active users that love to help others. They always are there and besides the automatic or admin given badges there will be also badges that are given by users as a thank you. All users will have “grant that badge” icon either below their post or under the profile and after getting “random number” badges from users, he/she will be automatically awarded with “Android ROM God” or whatever, predefined by moderation/administration.
Alternatively:
If user generates certain amount of likes in particular category - gets particular badge designed for that category.
Maybe this one is on your list, haven’t checked yet.