Skills

General

With the little information available, one could guess that the character skill-system will be somewhat similar to the one in EVE Online, where there's a big list of possible skills that one can train over time (maybe even while offline). Some skill may require others to be trained to a certain level. Trained skills will unlock certain abilities/spells or increase their efficiency, power, range...etc.
Let's be clear that this currently is mainly speculation. Here's the most significant quote from a developer in that regard:

When it comes to leveling, we don’t have a global character level, but we have skills, and these skills have a leveling system. We will give more info about the roles, the skills, and how they interact (or not) at a later point (before too long™).