Colin during PAX:
Colin for the MMORPG interview:
Based on the information we have, it seems like we are dealing with a gating system that's founded in vertical progression. It feels similar to GW1's reputation grind or D3's Paragon system. It seems that players will grow stronger, rather than simply progress through the game.
Now, the question isn't if it's good or bad (although feel free to share your views on it), the question really only is; how do you perceive this system? Do you see it as a horizontal progression system or do you view it as a vertical one? Why?
True horizontal progression allow you to jump straight to F and then to Z without getting A, B or C first. However getting Z won't make you more efficient than getting A would, it just makes you more efficient for the case where Z is a better choice than A. Having Z won't invalidate any (or most) of the things you previously obtained or that you can obtain, since with everything you get you become more versatile instead of more powerful - the definition of horizontal progression. Typically, you obtain important pieces of your capabilities early in the game (e.g. GW1's Frenzy is the first skill that a warrior earns).
Horizontal vs. vertical progression refers to player efficiency under certain mechanics of the game. It's too early to say how efficiency is going to be affected. It does smell like a gimmicky and thus failed horizontal progression system (for example, the hang glider is either fantastic meaning everyone will go for that first, or it's pointless except in certain special cases), with ranks for each type of mastery sure, and there may be gating hidden in that somehow.