As Patrick mentioned before, there are no "push the button to become invisible" mechanics planned as for now. And that is very cool only under 1 condition - a lot of rendered terrain (and decent distance of terrain rendering, just like in Heroes and Generals, where stealth and positioning decide everything and bushes, grass and trees are the main tools to do so), which I can not really imagine in the same pool as large scale battles. Optimization kills most of the terrain most of the time, big and small. I personally would love to lurk in bushes and ambush people, not just going in stealth by pushing a button. Do you see the "natural" stealth happening and how do you think this will affect Eldar gameplay? Mostly Striking Scorpions and Rangers if they will make it to the game of course.