We already know that the iPhone's EU launch this year will only be into a few key markets. The report suggests that these will include (And may be limited to) the UK, France and Germany.
T-Mobile we already know is doing Germany (Despite no confirmation, it's the worst kept secret in the whole affair), France we had been hearing would be on Orange which this report confirms and the UK will be on O2 as I predicted and hoped for.
The announcement is expected to come a the IFA consumer electronics fair in Berlin, which runs August 31st through September 5th. This is a far more likely time frame than Apple's own European event, which is later and which I expect will deal more with iPod and iTunes - specifically, I expect them to finally roll out better video content on European iTunes stores.