In a press release after the Apple special event announcing the iPad yesterday, VOIP solutions developer iCall has confirmed that the latest release of the iPhone SDK will now allow developers to integrate support for VOIP over 3G data networks after being previously restricted by Apple as a server-side block.
In response, iCall has made available the latest version of its iCall application for iPhone/iPod Touch with support for VOIP over 3G on the App Store.
The recently announced iPad features 3G support and a built-in microphone, presumably for VOIP usage as the 3G radio used in the iPad does not support GSM voice calls.