While I've been out of the game for months, I really don't understand the level of anticipation toward an expansion pack, especially from that trailer.
The trailer includes:
>Trahearne (one of the most hated characters that took over the personal story)
>Destiny's Edge, with Caithe lecturing (again)
>A dragon. (shocking)
>Moar epic battles/world on fire
>Other long-running (and dull) living story characters
>Tyria is in danger, trusted friends become enemies, yadda yadda
I know it's cynical, but anyone who has followed the game (and hype train) should long ago have learned to not create your own hype, let alone ride the train when we're told it's on the way.
Let's be clear about what an "expansion" is:
-Permanent new, replayable content
-New game features and/or activities
-World expansion
-New playability (e.g. race, profession)
If people seriously get that vibe from this trailer and are pumping themselves up, I'll feel no pity when they're disappointed. The devs themselves shunned the expansion model explicitly for a "living story", and new professions would violate the hell out of their core philosophy and their early development findings that couldn't squeeze more than 7-8 unique professions into the game (ranger, in particular, almost didn't make it). There's literally no point to an assassin (thief) or ritualist (guardian/elementalist/mesmer) other than to do similar things with different fireworks.
I'll believe in an expansion when they announce an expansion.