Photosphere requires a gyroscope which almost all phones since 2 years have. So it will work. The reason it's not included in CM and only in Nexus devices is because it's not open source i.e. a part of AOSP. It's a closed source app called GoogleGallery.apk because it uses Google's proprietary street view technology. That said, just putting the GoogleGallery.apk and it's related lib files in a CM ROM, it'll work. So even if it is not included Xperia Z (I think I won't be), it should be possible to copy/flash the GoogleGallery.apk and related libs into the system partition and have it work.
XDA Developers was founded by developers, for developers. It is now a valuable resource for people who want to make the most of their mobile devices, from customizing the look and feel to adding new functionality. Are you a developer?