Daring Fireball has some great analysis of Gizmodo and the Prototype iPhone including some revelations such as the quote below:
According to several sources (of mine) familiar with the project, "N90" is Apple's codename for the fourth-generation GSM iPhone, slated for release this June or July. "DVT" stands for "design verification test", an Apple production milestone. The DVT milestone is very late in the game; based on this, I now believe that this unit very closely, if not exactly, resembles what Apple plans to release.
Very interesting... some people seem to really like the new design, some aren't too keen. I'm warming up to it, but people have a point in that the screws are very un-apple-like, and the design looks a lot like the borning "normal" HTC smartphones. Guess we'll see in the June/July timeframe...