Apple posted a new KB article on Friday outlining the features and also offering iPhone OS 3.0 upgrade for all iPhone users free.

Notes are below:

1. Peer-to-peer connectivity requires compatible applications, which can be downloaded from the App Store when available.
2. The original iPhone does not support using Bluetooth for peer-to-peer connectivity. It can use Wi-Fi and cellular data networks for peer-to-peer connectivity.
3. MMS is not available in all areas; fees may apply. See your carrier for availability.
4. Internet tethering is not currently offered in the United States and some other countries. See your carrier for availability.