Orchard BlogML Module
The Orchard BlogML module allows users to import blogs from other blogging engines in to orchard, and also allows users to migrate there blogs out of orchard.
There is a brief walk-through on http://www.themayneissue.com/memorystream/blogml-module-for-orchard-0.5-cms-now-available
If you have any issues please log them in the issuetracker. If you would like to get involved please raise a query in discussions.
Happy Blogging - Nick Mayne