As always, Sony has released a new goody for the advanced Android users, who like to tinker around their Xperia devices. This new goody is a flash tool that will provide a simple GUI to flash stock ROM on your Xperia phone, in case you get tired of CM, or any other custom ROM.
Available for download now from Sony Developer World, the tool is currently in beta and only supports select devices (read: Xperia S, Xperia arc and Xperia arc S), but company is working on it and soon we should be able to use this tool for most of Xperia smartphone available today.
Another drawback is the availability of stock firmwares currently in the flash tool, but company is promising to fix that too soon.
To use this tool you need unlocked bootloader on your phone, which you would already have if you have a custom ROM installed.
Company noted in the developer world:
At Sony, we have been supporting the custom ROM community for a long time, and our unlock boot loader service is very popular. We know that many of you are advanced users, who like to try out different ROMs on your Xperia™ smartphones. But until now, there has been no way to go from a custom ROM to Sony software. We are proud to provide high quality, stable software for our phones, and with this new flash tool, you can now flash standard Sony software on a Sony Xperia™ smartphone which has the boot loader unlocked. However, please note that the boot loader of your phone still stays unlocked.
You can read more about Sony Flash tool or download it from here