http://elderscrollsonline.com/en/news/post/2013/12/04/creating-eso-designing-skill-lines
didn't see this posted yet. I love this part:
"A question we often see is, “Why not go classless?” In the end, keeping class skill lines exclusive while opening many other skill lines to everyone worked best—choices stay important, but everyone has freedom to choose from a large pool of options. It helps us encourage diversity while still providing choices, and it allowed us to emphasize multiplayer strategy—members of the different classes have access to their own skill lines, which creates opportunities for you to work with your allies, coordinating your unique skills and adding depth and variety to team gameplay.
Your class is an important decision to make, but it doesn’t chain you to any one playstyle. Every class has three of its own skill lines, each with different skills that are thematically related to the class. Combine those three with the many, many other lines available to every character, and each member of a particular class can be wildly different from the next. If you don’t want to, you don’t have to spend a single point in your class lines. However, you’ll know when you see a Templar who has decided to focus on his or her class abilities."