Rotations are announced every June, and take effect every September. There are still some pretty significant events during that time (US Nats, LCQ, and Worlds all come to mind). We may or may not follow our usual pattern this year, so I wouldn't recommend dumping too much of your collection until you know what the next rotation will actually be.
Nobody really knows. People can guess but theres always the chace that they are wrong. All I know is the fact taht if GE goes out they are taking unown g with it and then gengar and dusknoir will dominate and g decsk will die to champ. With this said I don't think they're taking claydol away from us.