I was really hoping that it would come out in June during WWDC, but I know that they will want to test the 3.0 software, which means it won't happen until September (WHICH IS KILLING ME). I've been patiently waiting since January, reading reasons why I should wait, but wanting one now for the fitness and notifications. But I still have to save up my weekly pocket money to be able to buy it anyway.
So my vote is around September when the iPhones are announced, or a month or so later so they can get the holiday sales. I'm hoping Apple do it earlier so it doesn't compete with iPhone sales....!