We knew it was coming but Microsoft has just sent out its formal invitations to the Windows Phone developer conference in San Francisco for June 20 and the tagline is "A sneak peek of the future of Windows Phone". This line strongly hints that we will see the next generation of Windows Phone in June (code named Apollo).
Other than the tagline, the invitation does not offer much else but from what we have seen previously, Windows Phone 8 will offer several key improvements over the existing platform. If you are a registered developer, make sure to check your inbox so that you can register to attend the event and be brought up-to-speed on the latest Windows Phone has to offer, fret not if you can not attend as Microsoft will make the event available to all via its Channel 9 site here too.
While we wait for the June announcement, you can take a look at a concept a Neowin member put together about his vision for Windows Phone 8.