Like This:
http://pokemondb.net/pokebase/500/how-do-you-get-rotom
This was asked before Black & White/2 was released, so edited it to include how to get Rotom in Gen V.
I don't know if it should have stayed like that for Gen IV and wait for someone to ask for Gen V, or if it is ok. I wanna make sure i'm not crossing any lines.
Yes, that is fine if you find out of date information.
Although for "where to find Pokemon X" questions, we probably have another question for each game somewhere.