Well... speed is a major issue for netboot right now. iMacs don't have gigabit ethernet, do they? And realistically, 100base just isn't fast enough.
In my situation (school network), the client machines are iBooks and iMacs. Try netbooting 50 iBooks over AirPort (try netbooting one over AirPort... 1.5MB/sec? No thanks); even try netbooting 200 iMacs over a gigabit line (even though the iMacs only have 100 Mb, that isn't a bottleneck - the Xserve simply doesn't have enough bandwidth to give to all those machines. Ideally, it'd be a multi-Xserve rig, but... $$$).
Connectivity speed is what's holding it back.
Ironically, as I type this on the G4, the iBook on my lap is getting installed with OSX Server 10.2. I'm running it as a testbed.
I'll be testing the tolerability of a majorly stripped netboot system over a 100 Mb line, and the rest of the package in general.
My major aim is to get AUC running, actually. But hey, OSX Server may nullify that need - we'll see. I doubt it.