Apple promotes every iPhone model as being scratch-resistant and the new iPhone 4 was no exception to the rule, especially due to the new technologies introduced in the production process of the glass parts mounted on the front and back of the iPhone 4. The iPhone 4 is covered with 2 sheets of aluminosilicate glass, the same material used for the windows of helicopters or high-speed trains, a very hard material chemically treated to be up to 30 times more resistant than plastic, so an almost indestructible material and certainly very difficult to scratched. Unfortunately, the "promotional texts" of those from Apple are just "words in the wind" and you have the proof above, that being the iPhone 4 terminal of the guys from Engadget and the respective scratches appeared after only 5 days of use.
Although the scratches are only on the back of the phone and are not that easy to notice, it is clear that the new iPhone 4 can be scratched, so you should be careful with it when you buy it. From my point of view, "myth busted".
