Or another way of thinking of the question, what one effect would you like to see if WvW had GW1's monthly flux effects as a feature?
For me, I'd love to see what would happen if you completely remove (/heavily disincentivise/make extremely difficult) the ability for players to stack on a commander/on each other in wvw. How they'd accomplish this I don't really mind so much. Hide commander tags on the main screen and only have the commander tag's position update every 30 seconds on the mini map, remove squads/parties entirely, turn the commander tag into an area placement skill similar to ventari's tablet, mess around with skill target limits, it doesn't really matter to me.
The reason I'd like to experience this is simple; I prefer large scale disorganised combat to organised. The moments of heroics feel more heroic, everything is more spontaneous and adaptability is key. It's like watching a more violent brownian motion.
Anyway, what would your change be, and why? It doesn't have to be for a lofty goal, it doesn't have to be a permanent change. I know it's been asked before but new discussion isn't necessarily a bad thing (and if it's been discussed very recently then my apologies, I didn't notice). I'm just curious.