Replacing a live blog

Hey there,
I’ve got a blog currently running with MovableType. I want to do a redesign and like some of the features I’ve seen in WP (the translation feature particularly since my site gets a lot of foreign visitors). So, I figured that it would be a good idea to do both changes at the same time.

My host (dreamhost) offers WordPress installation so tht’s not a problem. I have a template tat I like and am going to take my time and customize it.

My concern is that, while I fiddle with WP, that I don’t accidentally overwrite any of the MT pages that the public can view (like the homepage). Is there any danger of this? Should I instally WP on another domain until I’m ready to replace the MT blog? (I’ve got about 160 posts and a couple thousand comments that I really don’t want to lose or mess up.)

I apologize if this post is repetitive.
Trevor