I've found this to be useful, after calling over and over and over, attempting to walk on water to get ahold of my wii...
When you call a store, don't ask a simple yes/no question.. it's too easy for them to get rid of you this way.
Just say "Hi, I'm calling about the Wii."
This will force them to formulate a thought, and believe me, it works! They'll start talking about it.... "well, with shipping usually this and this happens, people who got one went about it like this and this...." etc... you might even get a shipment date out of them.
They know the score, even if they're discouraged from giving away info on the phone. Lots of staff are pretty nice and helpful, and they feel good about sharing their knowlege... Whereas if you just ask if they have any Wiis, it's begging for "No. *click*"