Lets go a little bit side topic here. When Guild Wars 2 frist started ANet stated that they did not put mounts into the game so people could not by pass content. And please forgive this correlation, look at every WoW expansion when it first came out, no flying till you are maxed level for the new epac.
Now lets take a look at the glider, it isn’t a mount. While it is a form of travel, they already stated that there will be areas that can only be reached once you have enough mastery in the glider. Even with that, since they have not gone into the Deep Dives on the glider I’m sure there will be more than just travel that we use them for. I can foresee Gliding Puzzles, fights that involve a large area to cover with the glider, heck, wouldn’t really surprise me if there was some sore of Glider Combat.
Even with all that I welcome the addition of the Glider to them game, as part of it’s evolution.