Solution
Personally, I strongly prefer OS X. But like others, I use OS 9 often for one specific program that is only written for OS 9.
Anyway, no need to argue which is better, as they each have their strengths, and both sides have been well debated already.
The point of my post rather, is to offer a suggestion for those of you who want the benefit of the new hardware and faster processors, but are concerned about the inability of the latest machines to boot into OS 9...
...the solution for your concerns can be found here ->
http://www.powerlogix.com/products2/pfdualg4133/index.html
These upgrades offer performance equal to, and in some cases superior to the latest machines (thanks to a larger L3 cache), are OS 9 compatible, and best of all, are cheaper than buying a new machine. I can't believe no one has suggested this option !
Bluetooth, Firewire 800 and such are great, but you don't really need them right now, and can potentially be added later via other upgrade cards. Why buy a new machine that can't boot into your OS of choice, when you can get one of these slick processor upgrades and max out your RAM for a fraction of the cost ?
Powerlogix just lowered their prices too. On the high end, get a Dual 1.2 GHz PPC 7455 w/ a 2MB L3 cache for $1099, or if you're on a budget, get an single 800 MHz PPC 7455 w/ a 2MB L3 cache for only $329 !
Sounds like a perfect upgrade solution to me, while we await the arrival of the next gen Macs based on the IBM PowerPC 970.
(No, I don't work for Powerlogix)
On a last note, OS X kicks ass, and is only going to get better. 9.2 is great, but face it, it's dead as far as Apple's concerned, and there's not much you can do about it. Use OS 9 when it suits your purpose, but it's better to embrace OS X sooner, rather than later, IMO.