In Windows 7, the ability to create a system image is available across all editions, including Windows 7 Home Premium. Fortunately, you won't face the limitation you mentioned with Windows Vista where only the business edition or higher could create a system image.
Windows 7 Home Premium, just like Windows 7 Ultimate, allows you to create a system image. This feature is essential for backing up your entire system, including the operating system, programs, settings, and files.
Therefore, when you upgrade to Windows 7 Home Premium, you can still create a system image to ensure that you have a backup of your system in case of any issues in the future.