Microsoft have sent out invites to the Windows Phone Summit on June 20th, together with the tagline “A sneek peak of the future of Windows Phone” to be held in San Francisco.

The next generation of Windows Phones are known to run an updated OS code-named Apollo although its release date is not confirmed it is suspected to be around the end of the year – Q4 2012.

Unfortunately Paul Thurrott has publicly said that he does not believe that the current range of Windows Phone handsets will be able to upgrade to run Apollo, so it looks like it will be released for new hardware only.

Allow me to set the record straight. No. It won’t happen. Not for the Lumia 900, and not for any other existing phone. It won’t happen partially, through an update that will deliver just some features, and it won’t happen for those who wish to pay for such an update. It simply isn’t happening. Sorry.

With iOS6 being unveiled on Monday at WWDC2012 June will be a big month for mobile OS previews.

Credit: Screenshot by Steven Musil/CNET