Unbelievable isnt it? But you must be wondering what made them do so....
First lets see the old iphone history :



Price : $600

Unlockable : Yes

Size
Dimensions : 115 x 61 x 11.6 mm
Weight : 135 gm

Display
Type : Touchscreen, 16M colors
Size : 320 x 480 pixels, 3.5 inches
Multi-touch input method
Accelerometer sensor for auto-rotate
Proximity sensor for auto turn-off

Ringtone
Type : Polyphonic, MP3
Customization : Download
Vibration : Yes
3.5 mm headset jack

Memory
Phonebook : Advanced, Photocall
Call records : Yes
Card slot : No
4/8 GB shared memory

Data
GPRS : Yes
HSCSD : No
EDGE : Yes
3G : No
WLAN : Wi-Fi 802.11b/g
Bluetooth : Yes, v2.0
Infrared port : No
USB : Yes, v2.0

Features
OS : Mac OS X v10.4.8
Messaging : SMS, MMS, Email, Instant Messaging
Browser : HTML (Safari)
Games : Yes
Colors : Black
Camera : 2 MP, 1600x1200 pixels, video
Google Maps
Widgets support
iPod audio/video player
- PIM including calendar, to-do list
Photo browser/editor
- Voice memo
- Integrated handsfree

Battery
Standard battery, Li-Ion
Stand-by
Talk time Up to 5 h

The new iphone 3G adds additional new features like high speed 3G,Youtube but will be a nightmare for unlockers as this version wont be allowed to be activated at home but rather at outlets.

Every action has an equal an opposite reaction and yes this one has too, you will find trade off between apple iphone price and the rate plan that means you have to spend more for service at a long run! Its obvious iPhone will be compensating from the carriers.
Also it means existing iphone users will have difficulties getting off their old iphones without 3G and will have to live up with it!
Ah but the old version has an edge over the old and it can be unlocked and used with other GSM networks which is admirable when travelling across other countries and can cut your roaming charges to great extent!

Whats next?
A 16GB piece would cost $299.
If you dont have one get one and give it a try.