If abilities are purchased with points via a skill-tree, will a character at max level have enough ability points to have all the abilities at useful (or max) levels, or just some? If only some, what sort of tradeoffs in other abilities will we see?

Both the skill point system and the talent system are being iterated on. Each character will have to make choices as to which skills, tradeskills and abilities he chooses to specialize in. Players should be able to gain exposure to a wide variety of skills but no one character will be able to master all skills. Players also have the ability to forfeit skills in order to pursue other interests. --Tigole