Prediction: Snow Leopard release date is June 8
The prediction is based on his research about when WWDC might be. Maybe, but WWDC could be a setting for a beta rather than a final release. I suspect that the ship date will depend more on Mac sales than anything else. If Mac sales are down, they'll figure that everyone is waiting for Snow Leopard so they'll have to ship something. If sales are OK, they'll hold off on shipping the OS until they need a revenue bump.
Personally, I want to buy a new iMac, but my practical wife is making me wait until Snow Leopard ships. She simply doesn't understand the coolness of buying a new Mac on the day it's announced. She also won't let me have an iPhone just because we can't get AT&T service where our new house will be.