Well, yes. I've done it. I betrayed ruby and rails, and migrated the blog to WordPress.
Mephisto is a nice try, but it's not as useable and powerful as the big player in blogging.
My boss said I should write my own blog in SmallTalk, which I'll probably do one day, but it's much longer to do than adding WordPress to my nginx+php-fastcgi setup =)
PS: I'll add feed redirection a bit later, for now no one will notice the migration for now