Swappable weapon skills
I’m guessing this will come in a future major update or campaign. My guess is that weapons will have additional skills added for each slot. You’ll still be limited to 5 active skills for two-handed, 3 skills for main-hand, and 2-skills for off-hand. However when out of combat, the little arrow would appear above the skill icon and you’d be able to pick from a couple different weapon skills suited for that slot.
I’d guess that not all weapon skills available for a given weapon would be available for each slot, but probably just two or three options per slot that were designed for that slot. For example slot 1 likely would have the no cool down auto-attack type skills, and the higher slots would have their unique options.
Great idea but Anet wouldn’t do it because it will be too much trouble for them to balance the skills.
I’d rather have more new weapons added than have them do nothing but add a bunch of new skills to existing weapons. Personally, anyway.