I am willing to not argue the point.
IF it happens it will be "not ready for prime time" according to you.
IF it does not happen the consequences are minimal to Apple as a corporation. It is fairly common for Apple to release "news" at WWDC only to have those announcements actually delivered later. I accept that. The stock market "expects" that BTW.
Apple can release "new" hardware with OS 10.4.9 (heck, it's stable!) anytime with no consequences whatsoever, and whether or not they give a "coupon" for a 10.5 update people will be "nearly" as happy. After all, the hardware delivered will do what it was promised to do on delivery (unlike my iBook G4 lemon still collecting dust waiting for Apple to save me).
But here's the thing. WHEN Leopard (10.5.0) is released, there will be a euphoria phase with early adopters and a "rage" of happiness. Many will submit bug reports, there will be whining over bugs. Some will claim lost data and kidnapped children.
Then 10.5.1 will be released. Calm will overtake the chaos and people's love of all things Macintosh will reveal itself to all blogs, websites, listserves, TV shows and newly minted internet TV shows and channels. It will be good.
The day will commence. Where the hell is 10.6?
Rocketman