What a fantastic idea.  It only took five years.  XMLSpy Home Edition - free. 

I'm guessing someone blogged it last week (I gave up on catching up on blogs since I was almost three weeks behind), but there's now a free home edition of xmlspy. Many of the cool features, including the schema editor, are available. However, the web services support, primarily the WSDL editor, remain only a part of the enterprise edition. [DevHawk]