Just had a look at the Karma forum and the majority seem to be about how there is a new iPod and the lack of a new Karma.

A large proportion of the users on Riovolution have huge avatar pictures and even larger banners at the end of their posts. Ick

The only vaguely interesting part was about the 40GB upgrades. Nothing really amazing or complicated though. It seems you just buy a new drive online, crack the Karma open, swap the drives and then get your dremel out.