Graham,
You must be talking about upgrading SDK's? In that case, we don't offer a product. The process is usually as simple as changing the references from 4.0 to 5.0 in your project. When installing a hotfit (5.0b to 5.0c for example) the process is just to reinstall the SDK, then rebuild your application. Nothing else required.
I'm not sure why you would have to go through this process when upgrading existing customers. Typically you would build a new version of your application with the newer version of the DotImage SDK, then deploy to your customer with an install package, or X-copy deploy. That's all you need to do. If it's a web app, then you will need to reactivate server serial numbers when upgrading major versions, but not for minor versions.
Infragistics offers a tool to upgrade all your Visual Studio projects from one version to another. I've heard about it, but it's not something we are looking at right now. But we can consider it for DotImage when upgrading major versions.
Bill Bither
Atalasoft