We've had a similar idea in mind for quite some time now, its on a very long list of ideas for things we want to implement. Not sure when it will be up for its time to be added, but it would have to be affter some other projects are implemented on both the SSRP and the Pointshop servers.
The system I have envisioned is very similar to steams achievements, where you unlock a bage and get a banner about the same size as the VIP icon that would go right below it. Of course all of the bages would have to be themed correctly and would most likely need to be custom inorder to look truly great. So instead of just encouraging the use of the forums we give people a fun thing to strive for across all of our services! Achievements could also function sort of like they do in wow and unlock special new cosmetic items that would have been added in the aforementioned big projects.
So ultimately good idea, but we have already though about a system for this. It will just have to be affter(with?) a few more important things. Im going to go ahead and just lock this thread. When we get closer to doing this we will open an official thread for suggestions!