The folks over at BBLeaks bring you all OS 188.8.131.523 for the BlackBerry Storm 9520. As noted by them, this is release is a non DRM version so it's not useful to all users out there. But worst case you may see some hybrid OS' come from it. Remember, if you download this one back up your data folks and be sure your device is compatible.
*OS Disclaimer - Please Read: Keep in mind this is NOT an official release and as such is not supported by RIM or your Carrier. If you choose to install, do so at your own risk and only if you're comfortable in the process of upgrading and downgrading your device software. It is quite normal during operating system development for certain features to be crippled or disabled while others are tested, and these beta builds often reflect that. They are not always better. Depending on your BlackBerry comfort level, it may be best for you to wait for community feedback on a build before deciding to download and install for yourself or simply wait for the next official release. If you require support, you will find it in our CrackBerry forums via our extremely knowledgeable community base - do not contact your carrier or RIM for Beta OS technical support (their first course of action will be to advise you to downgrade to a supported OS). Follow the links below for more information and instructions. *BBLEAKS