Voyant Tools is fairly flexible for ingesting XML. You can define an XPath expression that points to various bits of metadata (title, author, etc.) as well as the body of the text. You can even define an XPath expression to divide a single XML file into several sub-documents (as one might want to do with several items in an RSS feed, for instance).
We have recently added an initial version of a special adapter for TEI documents that pre-defines these XPath expressions. You can use this feature by selecting the TEI option from the loading texts screen.
Alternatively, you can use this parameter in a URL such as this: http://voyant-tools.org/?inputFormat=TEI&input=http://www.dh2012.uni-hamburg.de/wp-content/uploads/2012/07/ab-321.xml&stopList=stop.en.taporware.txt