Serene Steelsaid: I think they bumped it back indefinitely due to the backlashes on the update cycle last year. "Guys we here you,.. so to apologise for the lack of updates, we're going to postpone this update as well." - Doesn't make much sense. But then there is a precedent for that kind of thing.
Those of us on lower-end systems would get major lag and FPS issues is certain weather conditions, just like we currently do with shadows. And just like shadows, it sounds more of a visual thing rather than something that affects gameplay so it probably could get a toggle.
I recall the snow affect at last Christmas's event caused a good deal of slowdown for some people, and there were lots of complaints about it. If that happened all over the world, and people couldn't even choose to not be at the Varrock GE to keep their frame rates up, the only possible outcome would be that lots of people wouldn't be able to play and would have to quit.