Colin Johanson, "A quick update on this one -> After feedback from presenting the original hero point count – we decided getting to level 80 will give you enough hero points to unlock all the core skills and traits entirely. Doing hero challenges (aka skill challenges) will simply allow you to earn all the skills/traits earlier before level 80. With the release of HoT, there will be options to spend the excess hero points earned from doing hero challenges in the world."   Update goes into effect on 6/23.
https://forum-en.guildwars2.com/forum/game/gw2/Skill-points-and-Spirit-Shards/first#post5187859