We do not reuse or reassign blog names on WordPress.com.
If you like, you can attempt to contact the owner of that blog and ask them if they would like to transfer it to you. You can do this by either of the following:
- leave them a message using a contact form (if it exists), or
- leave a comment on an existing page or post requesting they contact you.
If you are able to reach the blog owner and they are willing to transfer the blog to you, here are the instructions they can use to do that:
http://en.support.wordpress.com/moving-a-blog/#transferring-your-blog-to-another-user-or-account
If they do not respond or refuse the transfer, you will need to select a different name for your WordPress.com blog.
Keep in mind we also offer an upgrade for custom domain names and you can use any WordPress.com blog URL underneath a custom domain. You can see more details about how domain mapping works:
http://en.support.wordpress.com/domain-mapping/