The YHOOL (not released) owner is currently working on a side project called YHOOL 1%. It will release on the 20th of may, and is on patch 3.3.5. Focus is on world PvP and strategy survival.
It is a simple version of the YHOOL concept in which all players are level 20 (start at 20, can't level up).
You start in a zone with some gear vendors (low level greens), class and profession trainers, and from there you jump into the barrens in a ruthless world where knowing the game and the people around you will be the key to survival.
This means everyone can group with everyone, and everyone can also attack everyone (unless in a group together). The goal will simply be survival, by teaming up and planning your adventure.