Skype has introduced Skype for iPhone 2.0. The biggest new feature being offered by the application is VoIP-based calling over AT&T's 3G network. There's one big catch, however. Skype-to-Skype calls, which have historically been free, will incur fees beginning in 2011.Both Apple and AT&T had initially prevented Skype from enabling VoIP calls over 3G networks. The companies eventually dropped that stipulation, but Skype had not updated its iPhone application to reflect that technical change. Skype fans began to wonder if it would ever permit its free Skype-to-Skype calls via AT&T's 3G network. On May 30, those fans got their wish.

"Using Skype on 3G has been the number one request among our iPhone customers," said Russ Shaw General Manager for Mobile, Skype in a prepared statement. "Using Skype on iPhone without being restricted to the availability of a Wi-Fi network will open up new ways for Skype customers to stay connected and make free or low-cost calls whenever they want, wherever they are in the world."

According to Skype, the new features included in Skype 2.0 are: near CD-quality sound for Skype-to-Skype calls using wideband audio on iPhone 3GS; enhanced call quality indicator; improved start-up time; and rapid access to the dial pad from the home screen.

InformationWeek questioned the reasoning behind Skype's new plan to charge for Skype-to-Skype calls over 3G. A Skype spokesperson explained, "Skype thought long and hard about this. Offering certain product features on a paid-for basis allows Skype to continue to invest in developing the innovative products that its users are constantly asking for. Skype knows its users expect great value from its paid products and believes the 3G calling capability delivers that. However, Skype is also committed to ensuring that the pricing for 3G calling on the iPhone will be in line with customers' expectations."

Skype said that pricing won't be determined until late this year. "Customer expectations" is a pretty vapid and meaningless gauge for what Skype might charge. At this point, we can only guess that Skype-to-Skype calls via 3G will cost similar to what Skype's fees are to call landlines or mobile numbers via Skype.

Skype-to-Skype calls will still be free over Wi-Fi on the iPhone. Skype 2.0 for iPhone is a free download from the iPhone App Store.