It's a bit early to say, but I think I've been bitten by the "'''Dual-band Airport causes kernel panic'''" issue described in [https://discussions.apple.com/message/12140636#12140636|this Apple Discussion post] many months ago. It's actually a Tiger bug. I guess it says something about my search skills that I spent MANY hours looking for a fix, and only after reluctantly coming to the conclusion that I was going to have to jettison nearly two dozen iBooks did I stumble upon the above link by accident.
It's only been hours, not days or weeks, since I applied this fix, but a couple of machines - that KP'd almost on startup - are still running. If my enthusiasm for this fix is dampened by reality, I'll post here again.