I love the reward system and gamification.
I mentioned this before, I think in a plugin thread but here it goes.
The idea is adding more options to "If User's"
Example "Tags" or reputation with tags.
What I would like to see is this
Someone on my forums has helped other readers and racked up 100 rep with the tag apple.
So the math
If user's reputation + (Apple - Tag) is > then 99 then add to group (apple)
This way we get people who are actually helping into corresponding groups and can reward them or offer next level help to them.
Maybe we can't mix rep and tag's, but even just having tag's would open another level of possibilities
People in the other thread thought it was a good idea, honestly don't remember the thread was a while ago.
If there is already a plugin out there doing this, please let me know, but would be awesome to have it in the core system.