Hey, I just went through this, here is what I did...
Downloaded WordPress BlogML Export 1.0a located at: http://blogml.codeplex.com/releases/view/171
Replaced my export.php with the "above" downloaded one.
Exported the posts (I noticed that it did export all of the post revisions, which can be a lot.
I removed extra posts or duplicates.
Imported the xml file through the Import/Export option in the BE admin.
Hope this helps!