I was pleased with the iPhone 3.0 announcement and actually ended up purchasing a new iPhone 3G device for myself so I can take full advantage of the new operating system. Rene Ritchie posted a detailed walkthrough of the iPhone 3.0 Beta 1 software that has me wanting this update sooner rather than later. I know I could get all the updates, except for MMS and A2DP, on my original iPhone, but I actually use MMS quite a bit with my teenage daughters since they do not have data plans. I also use A2DP quite a bit on my Nokia devices to listen to music as I work out on the elliptical.
There are lots of rumors of new hardware being announced, but I am sure it will be at least four months away and with my track record of mobile devices that is a long period of time to use the iPhone 3G.
The most compelling new features I saw in Rene's post were Spotlight, cut/copy/paste implementation, and landscape keyboard. There will be more in updates over the next couple of months and the over 1,000 developer APIs should result in some great innovations as well.