I thought of this in the two hours I spent reading the arse end of this thread instead of sleeping.
Why not, a simple ban on all the auto-weathers, BUT- instead of essentially dumping them into the Uber tier, make a "sidegrade" Weather tier instead. It would be whatever is in Standard, plus the auto-weathers, leaving Standard to the likes of Sunny Day and Rain Dance as it's been since 2nd gen.
This way, there would be two environments providing results on suspect testing. Not only could you skip this Sand Veil/Sand Stream nonsense, but you could get rid of Drizzle+Swift Swim too. (Having no complex bans is better than having complex bans, I'm assuming.) Let the full force of auto-weather slog it out for a couple of months, and if it collapses in on itself, so what? Standard is still healthy. (A proper test for Manaphy without Drizzle could finally be done, for instance, and if it passes, simply let it into Weather Tier too.)
Ubers started as the Standard banlist, and that turned into something legitimate, despite being a dumping ground for things that made the competitive scene less interesting. Rather than calling foul at every single weather abuser in the game (because if Snow Cloak is getting brought up already, it's only a matter of time before Solar Power and Ice Body are all that's left and then they'll be up for bans) I think it might be quicker and more constructive to simply make another tier, even temporarily. Let the Weather tier develop on its own and you might shake out some surprises that you simply won't discover if you just ban everything, and meanwhile, the Standard tier will still exist.
Pros:
-People who want auto-weather are happy, people who don't want auto-weather are happy
-One simple clause replaces a (potential) number of complex bans, or bans that are designed to be "simple" but take out "bystander" Pokémon needlessly (Glaceon, Sandslash, etc)
-Two environments means twice the results automatically with each test
Cons:
-If there's a Standard +Weather, it follows that there could be a UU +Weather develop separately from regular UU (I don't think it's too likely, but it could happen- will probably just be UU + Drought Vulpix/etc, though)
-The idea of making a whole new tier to examine and solve a problem is not something that should happen often, but then, this will be the second time, so there is some precedent.
-We'll be right back to square one if the Weather tier crashes and burns right away. However, if it does stabilize into something, it will be useful because it can be directly compared to a metagame without auto-weather.
Summary:
-Auto-weather abilities are banned from Standard. Weather tier is Standard tier with all auto-weather abilities permitted.
-Changes to Standard tier not related to auto-weather abilities affect Weather tier automatically. (ie. if Manaphy is allowed into Standard tier, it is automatically allowed into Weather tier, with no consideration given to its effect on that metagame.)
-After several months of "deal with it", the Weather tier should provide data and results regarding the auto-weathers in an environment where "just ban it" isn't an option, while keeping the metagame developing in the Standard tier without all this futzing about with clauses and bans and dismantling Pokémon. The important issues can resume being discussed (ie. why the hell is Stealth Rock not banned yet, overcentralization this, no counters that, etc).
Thoughts?
~Uiru