I'm not in a queue to buy Leopard, nor have I ordered it in advance. It's a good step (if not leap) forward from 10.4, but I don't need to get a fix that quickly. I'll get it sometime, no doubt, but will wait until it's ready.
Why the hold-up? No, it's not because it doesn't have Java 6 (expect that to come along sometime later with the ADC downloads), even if some of the more Java fanbois are confidently predicting the death of Apple due to the lack of Java 6. They said the same thing about the iPhone, right? Didn't seem to do their quarterly results any harm.
The real reason for waiting is that subsequent fixes will be available; and I'm waiting for one in particular: R/W ZFS. The Leopard install has support for read-only ZFS (at least, according to their public pages) and I want to be able to use the R/W ZFS. Ultimately, the plan is to have a ZFS RAID array to replace the current RAID-1 mirror that I have; and I want to be able to use it from a Mac OS X boot disk.
Whilst I could get a DVD now, then later (when R/W ZFS is supported) build an array, if anything happened and I needed to re-install from a DVD, I wouldn't be able to read/write to the array (although I could read from it). I've had enough experinces with OSs generally that leads me to think that having a good known boot disk that supports these things is a generally good idea.
And, as it happens, I'm not getting an iPhone (yet) either, though that's more to do with the fact that I'm contracted through until mid next year. Helpfully enough, that's probably when the next iPhone is coming out (watch the MacWorld Expo in Jan for an announcement of an iPhone+GPS). Still, as with both of these things, it's when, not if; but the answer is "not yet" to both.