You seem confident.
Then maybe, JUST maybe, they are waiting to announce it so they can announce it together with the new Retina MacBook Pro?
It's just that it's happened every year that I can remember. I think the rMBP refresh would be alongside 10.9 rather than a promotion, but maybe.
I'm just trying to stay optimistic.
I think it is a little bit probable, because.. why else haven't they announced it yet? I can't think of a reason.
The only possible scenario is that they are waiting for the first day of summer which is:
Friday, June 21
The First Day of Summer (Summer Solstice) 2013