Actually, a few months ago, the Character Builder had an update that modified the XML character sheet output. The change was in the April change notes
. The relevant part was:
XML character sheet: this export now has a new section that is friendlier to third parties, since it does not need to reference the rules engine. This should help modders create their own display options by reading the XML output.
It sounds to me like it wouldn't be a problem to use that xml character sheet (not the actual character save file itself) as the basis for alternative formats. You could have an XSLT to display it on a web page, for example, or maybe convert it into the MT token XML format (creating a token with pre-populated properties), etc.