Yep. My new bike came with 9 speed and it would have cost me money to convert it to 8 speed
The 8 speed setup uses a wider chain. I know one custom bike builder who recommends the 8 speed for touring on this basis - they last longer. Personally, while he may have a point, when you consider how long it takes to wear these components out in normal riding, is it much of an issue? (different when you're out the back of Bourke I know but when doing day trips from home ...)
Upgrade your bike in the most efficient way practical, then dream up bogus reasons to tell your mates next time you're having a bull session in the shed.
Richard