I have a blog for my Rat Terrier dog, Mindy. But since we just added a new Rat Terrier to our family, I wanted to start a new blog with a new domain name. I didn’t want to lose all my original blog entries and comments, etc.
I thought I was going to have to import data from the old MySQL database, and that was kind of a scary thought. But it turns out it’s much easier than that.
In your original WordPress blog, click Export under Tools

If you want to choose a specific author, select it from the pull-down list, if you want all posts, then choose "All Authors"
Then click the Download Export File button. Save to your hard drive.

In your new WordPress blog, choose Tools>Import

Choose WordPress from the list of blogging software.

Browse to the location you saved the original exported WordPress file. Then click the Upload button.

Before your posts are imported, it will ask you if you want to create a new author, or map all entries to an existing author. I chose my existing author "Admin" so all posts will be consistantly by me.
If you want to download and import file attachments, check that box.
Then click submit.

WordPress imports all the entries.
There will be some additional tweaking on my blog, such as links and comments made by me on the original blog…but the search option in WordPress helps a lot to find all descrepancies.
I’m working on a similar project, but it’s a wordpress mu blog, or multi-user. I know I can export and then import but figuring out how to attach each of the blogs to their authors has me puzzled. it seems from what you’ve shown here that WP might offer an option to say attach blog A to author A, and then go through each one maybe?
Comment by Allison Sheridan on February 8th, 2009