Ok my SONY WP theories since you ask for it:
So first theory I been doing research and found out that Sony will have a small stake/shares with the pc division which it going to stop producing PC globally however will keep selling in Japan so I'm assuming they could still use the VAIO name with permission from the new owners which are a Japan private business. So they could call it under VAIO still to not confuse it with the Xperia range however the mobile division will of course be the ones working with it. And have all the Sony apps on the device exclusively.
Second theory they make it under the Xperia name however they will call it the SONY XPERIA X1 so it would be kind of similar name to Windows Mobile Sony Ericsson x1. And have all the Sony apps on the device exclusively.
Third theory is they completely rename it but keep the SONY part of course and have all the Sony apps on the device exclusively.
Fourth theory is they will only release one flagship phone that will have all of the Sony apps and see what happens.
Fifth theory I buy SONY and make WP devices.
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