iPhone OS 3.0

[DumBlonde]

Anyone know the release date and/or cost of the new OS for iPhone 3g?

[Milvus]

The mac journalists think it will be released in the summer. There are partial beta versions available for registered developers now.
Apple haven't charged for iPhone OS releases yet

[Gromit]

The Apple Worldwide Developers Conference takes place in San francisco June 8-12 and the new iPhone and other new Apple products will be unveiled then.

Th ne iPhone when it arrives will have v3.0 and is usually delivered to existing iPhone users as a free download. A small charge is made for iPod Touch users.

[fo3nix]

Yes, for iPhone 3G it'll be free.

For original iPhone, it may have a small fee attached (same as iPod Touch, due to Sarbanes-Oxley accounting law after the Enron scandal), and won't have all features that you might get with iPhone 3G.

Due July time. It'll be showcased (probably with new hardware) at the WWDC in California.