Adds a new datatype that can come in handy when working with multilingual sites and you don't wan't to replicate a certain content/media node for each language. A property of this type will add a textbox(or textarea) for each language that is set. Usefull for example on the alt text of an image in the media section.
To fetch the correct language value you can use the following in xslt:
/propertyAlias//value[lang(Culture:GetName())]