I wouldn't be upset about these poor numbers if users could slide a charged battery into their phone. But iPhone have sealed batteries (you could take them out if you choose -- but Apple doesn't market replacement batteries). If you have dreams of replacing a Blackberry or Windows Mobile device with a new iPhone, you might want to think twice about it.
As for the price, the new 3G handset is cheaper than the old one. The new 8GB 3G retails for $199 with a two-year service contract. The 16GB model sells for $299.
But, because Apple cut the price, and cut the profit margin for AT&T, the carrier raised its monthly service prices. Those fees are now exactly the same as what AT&T charges for any other smartphone.
If you do the math, even though you save $200 on the price (compared to the old phone) you're paying $15 more per month, or $360 more over two years, for the service. That comes out to the new phone actually costing you more over the life of the contract. You are getting a 3G phone.
To sum it up: The iPhone 3G is the best consumer-oriented smartphone device on the market. All the new features make the 3G even better than the original. At the same time, the new iPhone 3G is not yet a very good enterprise device.
If you have an original iPhone, you should definitely upgrade it for free and enjoy all the spiffy new features.
If you don't have an original iPhone, don't need Microsoft-based corporate email and carefully adjust battery-draining features, then the iPhone 3G is just plain fabulous.