A few questions about the iPhone?

Hey guys, I am buying an iPhone and I am currently waiting for the 3G iPhone to come out.
1. When is the 3G version coming out exactly?
2. I am currently on a family plan with my parents and siblings, i have unlimited texting and 1400 minutes, but i was curious, do i need any special plan for the iphone? like a data plan?
3. and for the people who have the iphone, how is it?

thanks.