Not really a designer for Spring XML config files (yet), but it already
- tracks references,
- provides an object editor with type and reference help,
- supports editing constructor-args including reference lists,
- and can finally generate and update those XML files.

No manual XML editing required!
(...except for editing properties - that's the next step!)
spring designer icon

So far it's been incredibly useful for a mid-sized Spring project.

Please check back regularly for updates, and please provide feedback.

download. (needs .NET 3.5)