Interesting development - updating to 10.6.2 has solved the 'broken architecture' issue for my OKI B410 driver, so I now have duplex printing back - though stupidly, you have to not only select the duplex option, but also check a new Two-Sided checkbox before it'll actually print duplex - redundancy abounds:

The hilarious thing is that I discovered this whilst printing out a letter of complaint to OKI UK about how they haven't fixed their driver yet! Oh well, saved some postage at least.
If it's brokenless, don't suffix it...