Thank you very much guys for your tips, and for pointing out Sheldon Brown's write-up on the subject.

I have actually yet to do any touring on this bike yet, just commuting and weekend rides. The pronounced wear on the rear must be due to my weight 230+ lbs and my Carradice saddlebag which sometimes holds an additional 10 pounds.

When I do begin touring it will be with a front rack w/ platform+panniers so as to distribute weight and not to burden the bike with any more rear load.

This is all very interesting, I've been riding almost a year now and it is really interesting getting to know the wear patterns of the various components, researching+shopping for replacements (the best part), and learning how to install them.

Thanks again guys!