I was checking my website hits and came across this article:-

Converting Data

Converting data over for my tests was rather simple. I used the Wordpress to Drupal converter offered by Prime357 , which made the work very simple. However moving over our live data had some extra obstacles. We were using a few special plugins in Wordpress to store our video data in the posts, plus to handle embeds easily. Before doing our final conversion I had to write a couple of short scripts to handle the converting of our media data so a new custom Drupal module I was working on could deal with it. I also decided to remove our embed plugin we had used in Wordpress and instead inject the embed code directly into the node->content field for Drupal. Once that was handled, I ran the Prime357 converter and we had the data fully ready for Drupal. The conversion program took approximately an hour to run on our 600+ megabyte database containing over 30,000 posts and over 800,000 comments. The time was really amazing considering that large amount of data.

The full article can be found here.