I read in my SharpReader(which will be replaced with RssBandit, by Carnage4Life) that Microsoft did release XML Notepad 2.0. Which is a quite nice tool! It makes Sheer UI development and debugging Sitecore Items much easier. Take a look at the screenshot below:
/sitecore/home/content incl. children
SC5.3B2-Shell.xml
List of the features in XML Notepad 2.0(list by Can Erten):
- Open source
- Comes with source code, samples (look at the directory you’ve installed)
- Very simple user interface
- Intellisense support based on XSD.
- Great navigation and adding of XML objects (like element, attribute, comment) simply by providing before and after points.
- Copy cut paste XML objects
- Find feature is also nice, it is possible to use regular expressions or Xpath language.
- XSL Output after the XSLT transformation.
- Error list similar façon of Visual Studio
Thanks to the ADO.NET Team Blog and Can Erten for noticing me. You can download XML Notepad 2.0 here… 
