Well, the video does seem to imply that the changes you make in the dynamic evens will be permanent, and thats not happening
Yeah, and thats certainly a discussion worth having. As it is the dynamic events reset way too often, and as a result they sometimes don't feel to have a lasting effect. This is something that can be changed over time, on the fly even, by ArenaNet, but as it stands it falls short of the promise of that video.
However, to just make a blanket statement "there's a lot of bullshit in that video" is to say that ArenaNet is lying/deceiving viewers and not to believe anything in the video. The point of the video (remember, it was released in 2010) was to explain the design philosophies that are going into GW2, and the goals of the game. If almost 2 years later they decided to sacrifice a bit of permanence for making the game more playable for people who didn't see the event the first time around, that just means there are design tradeoffs. It doesn't mean they are full of shit. To imply that they are is dishonest, and does not help anyone.
Edit - Just saw you responded. Thanks for at least explaining your position. To your points:
1) In PvE, you still most certainly grind. You go from dynamic event to dynamic event (see #2) and repeat the chains over and over which is the only way to really level up. Hell, you end up repeating the same shit in GW2 pve from what I've seen than most other recent MMOs which have a large amount of unique quests to take you to level cap.
If you are doing the same events over and over again, that is entirely because you chose to. There is no shortage of content that you should feel the need to run the same events repeatedly. If you have completely maxed out a zone and still aren't high enough level for the next zone, there are at least 2 other zones (in the Beta, there will be more at release) in the same level range. Aside from that, WvW is a great way to level up, crafting gives some decent level ups as well, and gathering provides a non-trivial amount of exp.
2) The part at 1:50 about the world 'not caring' that you're there with, and I quote, "the boss spawns 10 minutes later" still entirely happens in GW2.
No argument here. They need to significantly increase the respawn times on Dynamic events. However, the fact that bosses aren't instanced, you don't have to complete most of a quest line and then wait in line after 10 people for them to beat the boss before you get a crack at him, and that when an event is completed it has an effect on the world, whether or not you personally completed the questline is a change. It just doesn't last long enough to feel like a significant change.