If you want to move your blog to another publishing platform, then it can be possible with Google now. Google has made it easier for you. Last Friday, the Data Liberation Team announced the Google Blog Converters project on their Open Source Blog.
Google made data portability a lot easier for Blogger users a month ago and with this announcement it appears they are offering easier portability solutions to WordPress, Movable Type, and LiveJournal users as well.
Friday's release provides Python libraries and runnable scripts that convert between the export formats of the above platforms. Future plans include synchronization tools between services that don't offer import/export features as well as support for BlogML.
Google has also released templates for hosting the conversions on Google App Engine.