You think they might have moved it to make it coincide with a product launch (iPod Touch, nano, etc or the new "iPhone 6" or "iPhone LTE")?
And no, it's not the "iPhone 5" it's the 6th generation phone! There's no reason to call it the "iPhone 5"
It's been moved because of the Olympics in London during July and August. Do you have any idea how much of a mess London will be during the Olympics traffic wise? It's going to be a joke trying to get around. It's bad enough now during rush hour and now imagine adding a couple million more people and reduced number of lanes (since some have been designated as VIP Olympic lanes).
It's going to be a grid lock of epic proportions. The transport authorities' solution is to put up posters telling people how awesome it is to walk to work as opposed to using their normal public transport, taxi or own car during the Olympics.