Tumbleweed
I thought, in true sandbox game players don't need to wait for events run by the devteam to participate in some activity. They go for it when they are up for it, and game reward them respectively. Tagged PvP in Ryzom is out of this scheme.
I always thought a sandbox meant that players were free to build their own content, not that demanded content (or rewards) would appear...I have never seen any players try to pre-organize large scale PvP (other than OPs of course). If you want it, set it up! The events team have showed time and again that they are willing to help with player driven content...make a story, set it up, and make it happen.
Give us a good RP story and NS will show (NS, my guild is not RP, but we like a good story). Or, give us a yell and we will help organize.