Apple gave developers copies of Jaguar at WWDC 2002 as well. Us non-developers consider them the lucky ones, but consider this... You're a developer, you get your preview release of Panther, get it home and installed, and try running your application on it, only to find out Apple changed the underlying OS so much that you now have to debug and rework your app so it will run....
Suddenly, you don't feel so lucky....
Seriously, it's a nice perk from Apple, but one that should be expected. Without developers, Apple would shrivel and die. Apple should do alot more than it currently does to accomodate developers.
An interesting article I read in some digital video themed mag had the lead of Adobes Encore DVD app talking about not releasing a Mac version. The two reasons he stated were that Apple had a great product in DVDSP, and that Apple wouldn't release info they needed regarding the G4 chip. Intel, on the other hand, provided Adobe with 2 engineers and all the info regarding the Pentium that Adobe asked for to optimize their app for the chip. Apple provided none of this. And this is Apples biggest developer.
Behavior like that must be changed and Apple must play nice with all of its developers, large and small, if it wishes to remain relevant.