I think that WEs are definitely in need of a new book. The two things that they did well both got nerfed. Skirmishers are obviously one of them, but the other thing that really hurt them is the change in VPs. The fact that you don't get any points unless you completely destroy a unit, or flee them off the table, makes an army dependent on shooting a lot weaker.
Against some armies they still have a viable build of Treekin and Treemen supported by archer units (for the banners if nothing else) and Life Magic. Against a heavily armored foe (such as my WoC) they really have no chance at all. I used to dread playing them, they just made for an excruciatingly horrible game for me. Chasing them around and rarely catching them, they literally drove me nuts. Now I see an auto-win when I play them.