I'd like to propose that, following Aldaron's proposal, the Rain article should be split into a Drizzle article and a Rain Dance article. Whilst Rain Dance is certainly challenged by the threat of Drought Ninetales and Sandstorm in general, it's gained some much better set up pokémon in Accelgor, Thundurus and Tornadus, and Swift Swim Poliwrath lets you muscle through Ferrothorn, Belly Drum or not. Double Dance Kingdra can be hard for Sandstorm and Drought teams to deal with, as if Kingdra gets a DD up, Tyranitar and Hippowdon get nailed by Waterfall whilst Ninetales gets KO'd by Outrage. Not to mention ridiculous attackers like Shell Smash Omastar that can keep up the momentum once Rain fades thanks to Shell Smash's speed boost, although it fares less well against Sun teams. Gorebyss and Huntail also become more viable as Shell Smash passers, plus you don't have to have Politoed wasting space to get your Rain up.
Rain Dance teams play considerably differently to most Drizzle teams and are still viable, so I think they deserve a seperate analysis.
