The migration seemed to go really well and I was soon tweaking with all my settings and modifying a few articles & pages etc.
During the migration there was a handy link to update your Windows Live Writer settings. I clicked it and it seemed to do something. However, when I went into Writer it kept giving me errors and asking for my username & password. It wouldn’t let you change the blog account settings either as it was trying to use my Windows Live account for authentication.