I will not upgrade to Mac OS X Leopard until the first maintenance update is released. I typically try wait for a few months to upgrade to the next OS iteration for the sake of letting others find the first wave of bugs ... and it's always a battle of the will. Especially when the in-depth coverage begins on the new release, and everyone is talking about the new cat ... and I'm still looking at the old cat.
The longest I've waited to upgrade was during the OS9 to OSX transition. The shortest time I've waited was for the upgrade to Tiger, which worked flawlessly for me from the start. Leopard, though, will be easier to wait for. In fact, this is the first OS release that is not filling me with anticipatory glee. For one, I don't feel that any of the new features are mind-blowing or urgently needed/wanted. Second, Adobe said that CS3 reportedly won't be Leopard-ready for a while longer ... even though I expect that the CS3 apps I run would probably work fine. And SuperDuper and DiskWarrior I hear are also not quite ready.
Lastly, Leopard came later than expected because of the iPhone and heavy, concerted marketing for it started really close to the launch date, which left me with the feeling that perhaps this OS might be heading out the door a little more quickly than it should ... perhaps I'm just being paranoid. That perhaps even Apple wasn't certain that an October release date was going to happen. That's the impression that I got, anyway. At any rate, it's a good goal to wait a bit ... as many people will tell you, if you absolutely, positively can't afford to suffer downtime, better to wait to upgrade and let the early adopters work out the early bird bugs. What's different this time is that I am waiting with far more patience. In the meantime, I am going to prepare for the upgrade and do some spring cleaning.