One close-up of the back of the black 3G iPhone shows that the material being used for the shell picks up very visible smudges and fingerprints, with the suggestion from Jeremy Horwitz that this may end up making the white model much more popular.
The iLounge article speculates that a Product (RED) 3G iPhone may be available in late 2008 or early 2009. If you're wondering if your current iPhone case or accessories will work with the the new device, Horwitz feels that products that are designed to work for either existing iPhones or iPod Touch should be fine. However, docks, cases, and other accessories that were designed only for the first generation iPhone will not work.
I, for one, am happy to see that Apple is making sure the iPhone / iPod economy continues to thrive!