it IS true. even meghan mcarthy has said it's true and she's already started her "new season fake out" game on twitter. the one she does before a new season starts. so my guess it starts late fall like in october. if not january at the latest.
The fifth season of any show is a milestone, it's also usually an indicator of the success of the show and how it might hold up in the future. If they flop on the fifth season the future of the show won't be so bright. I'm hoping they do it right.