I'm pretty convinced they haven't been mining much at all now. They may have just started in the last 24-48 hours.
There's not any other credible reason to delay releasing the address.
Or they've had very bad luck. That's likely the reason for all the delays about posting the address. They're embarrassed about how few blocks they've found (likely zero)
Excuse me if this issue has been beaten to death already, I've most likely just missed it as I've been trying to read as little of this thread as possible.
What would be the negative to running a private pool? Wouldn't that be secure and give us the ability to monitor hash rate live? There wouldn't be a pool fee... I mean, if you are solo mining anyway, I'm just not seeing the negatives.