OK, I have decided to answer some of the questions here. Please don't put every single word on the scale again or dig into every single detail - in the end, the only thing that will provide absolute certainty, is the update, and the retrospective view a couple of weeks after the update. Before that there will always be questions or this "fundamental uncertainty".
1. If there is "no item treadmill" then is, with the "Ascended" items, with 100% certainty the maximum reached, or will the whole thing start again all over again in a year or two?
We simply cannot give you a percentage. You saw how an old announcement about Exotic/Legendary weapons was treated "But back then you said..." - so if I tell you that with 100% certainty there will never be anything higher, that would not be helpful. Even if in e.g. Guild Wars 1 we never made any substantial changes, there were still green items (also in later chapters) which enabled weapon combinations that simply were not achievable in the Prophecies times (15-staff of energy for example), and still it wasn't a gear treadmill.
2. What will happen to the gear from the other dungeons? Will they be upgraded later or are they (and thus the dungeon) suddenly outdated?
As can also be read in Chris Whitesides statement, we will make adjustments so that they apply to both new and existing content. No, existing dungeons will not become obsolete because of the new items. And this applies not only to the unique nature of the exotic armor designs that can only be obtained in these particular dungeons.
3. What happens to crafted equipment? Is all the effort that we spent on crafting for naught? (if I had known right from the start that Exotics would suddenly not be the maximum stats anymore, I would have saved a lot of time and money and just kept my Rare requipment).
That's what Chris meant by "new features" affecting "current content". We also look at the crafting professions (possibly not immediately in this update - that would be specifically Jewelers here), but crafting is definitely an important core concept of the game as well and should not stay out of this.
4. The statement was "the community wants progression, so she gets it" (simplified). If that was the motivation for the Ascended items, what happens when "the community" is finished with this progression? (follows up on #1)
That's why we do not speak of gear progression, but of features that enable a progression, without constantly requiring the introduction of a new tier of items. The new "Agony" condition in the "Fractals of the Mist" dungeon is such a possible progression. That dungeon has no end! However, it becomes increasingly more difficult. Through the 'agony' we introduce a hurdle in this dungeon, that you have to overcome either by skilled play or with the right gear - or later with both - to move forward. The whole dungeon is designed to offer you something where you, as a trained team, can see "how far you can get" without it being the goal "to complete the dungeon".
5. In Chris's statement there was something along the lines of "we want to close the gap between Exotic and Legendary". My question is, what gap? Exotic and Legendary were equal in stats, the difference was only the time invested. If the "wall" is only time spent, then why raise the stats?
The gap is indeed the time, or the method of acquisition. For many players, Exotic gear is a short-term to mid-term goal. And the Legendary gear is intended as long-term goal (but we have found out that player absolutely want to get their "Legendary" as fast as possible - that's why we are making changes in this area). So after this change we will have the Exotic gear as short-term (direct) goal, the Ascended gear as mid-term goal (on the side, as it's not available as a complete set right from the start) and the Legendary gear as long term career goal for your hero. You can have different opinions on the raising of the stats - as you are actively discussing here, and we are well aware of that. But I hope that you realize, that the "Fractals of the Mist" and the Ascended gear make sense as matching mechanics.
6. What happens to the Triforge Pendant / What happens with the Ruby/Sapphire/Emerald pendants?
They will still have their niche - and possibly provide better services than the objects with infusion slots initially will. But especially in the "Agony" field they will increasingly lose importance. Please note that also in Guild Wars 1 there were regularly objects that were extremely sought after and expensive for a certain period of time, but then eventually lost their value because of an update. Victo's Bulwark for example is one of these items, the old 20/20 Rockmolder is another. This will always happen in MMO's - with or without gear progression - and it's a normal process. Even in Guild Wars 1 - despite the lack of gear progression - players would not always stick to the same set of equipment that they had once collected at the beginning (even if the system made it easier for them), and even there that was not (always) because of the appearance, but because of minor value adjustments or combinations that would benefit a certain build (for example Deeproot's Sorrow for the Illusion Mesmer).