I looked around, and apparently this game will have a dynamic weather system, which is great to hear! But I've been unable to find out a few less important, but no less interesting facts about it.
Will GW2's dynamic weather system...
1. Occur often? I understand something happening sparingly can make it that much more awesome, but a lot of games these days seem to use their weather systems a little too sparingly, resulting in things like very rare rain. I want escapism, not typical Australian weather! :P
2. Have a lot of variety? Having rain and storms is great, but can we expect to see things like sandstorms (where appropriate), snow and maybe even heavy winds / cyclones? Apparently weather will influence, and be influenced by dynamic events, so one would expect some more extreme weather created by more powerful beings, here's hoping.
3. Be constricted to seasons? Whether it's shorter, ingame seasons or actual, real-life seasons, this could be interesting. It would reduce the allure of the usually rare rain and storms significantly, however.
4. Actually have clouds? This may seem like a silly question at first, but a few games seem to make the mistake of having it rain when the sky is still sunny, or the cloud cover is sparse. Building on this, will it be possible to see if weather is coming by the direction of the clouds, or will they merely serve as background flavor?
5. Influence our character? I don't mean stats-wise or anything, that'd be silly, but more cosmetic details like your armor becoming soaked, or your Charr character's fur dripping in the rain would be very welcome, especially coming from a game which has already shown itself to look quite good from a graphical / style point of view. Perhaps you could even buy an umbrella for your town clothing set.
Yes, I'm aware these questions are probably too esoteric (or NDA breaking) to answer, but I thought I'd put them out there anyway, for discussion's sake. What are you expecting from GW2's weather system, something more ambitious, or simply a bit of flavor?