The only thing Steve Jobs announced is the date when the iPhone 3G is going to be available in 22 markets around the world.

As we get closer the discussions and rumors heat up on how the July 11th will go down in detail.
AppleInsider reports that O2 will already open their stores at 7:05am or 7:02am, ahead of normal shopping hours.
A more exciting rumor is for PAYG iPhone 3G customers. Apparently after 12 month the iPhone 3G will be unlocked, like other PAYG (Pay as You Go) phones O2 is offering. The cost for unlocking the iPhone 3G in 1 year would be £15.
More details on AppleInsider.