Apple UK Special Event for 18th September - iPhone?

Macworld have broken the news of an invitation they have received from Apple UK. A special event is being held in London on September 18th. The invitation states "Mum is no longer the word". This sounds like we might finally get UK launch details for the iPhone, that they have been keeping under wraps over the past few months.

**UPDATE** A visual of the invite can be found here over at MacFormat.