As you all know, Steve Jobs announced the iPhone 3G yesterday at the end of a long WWDC keynote. The new device has 3G, GPS, and long battery life. However, your data plan rate will increase $10/month too. The rest of the hardware is the same so my plan is to skip this small update and wait to see what may be announced next January at MacWorld.
The iPhone 2.0 software update will also be coming in July so I do plan to update my current iPhone to get Exchange ActiveSync support, which will be great. Apple also announced their new MobileMe service that looks awesome and I think this is the bigger announcement than the iPhone 3G.