The iPhone has been a very successful product since its release not too long ago. The three biggest bones of contention (the battery, the software and the price) haven't stopped many from buying it, but Apple has sought to increase the phones appeal so that more would pick it up. The biggest issue of them all, the price, likely kept many away - $500-600 on a phone was not easy to swallow.
Apple has done themselves and all their non-early adopting fans a favor by shifting the lineup and altering the price of the iPhone. First and foremost, the 4GB unit will disappear- only the 8GB model will be offered in the future. Apple cites poor sales of the 4GB unit as a reason.
More importantly, however, they didn't just drop the 4GB unit and expect people to just deal with the higher price of the 8GB model. Instead, they have decided to put a huge dent in the price of the 8GB iPhone, bringing it all the way down to a mere $400. That is cheaper than even the 4GB unit originally retailed for, and brings the iPhone much closer in price to other comparable smartphones and PDAs. Not only does this open up the iPhone for a lot of potential buyers, but it also gives Apple plenty of room for higher capacity units in the near future.
At $400, the iPhone is looking a lot better than it did a month ago.