You don’t need an upgraded account to use Haloscan with WordPress, but you do need an upgraded account if you want to export the Haloscan comments and import them into the WordPress commenting tool.
The problem with continuing to use Haloscan is that the old comments are tied to the post ID numbers that were used by Blogger. When I installed WordPress, it imported my old posts into a new database and blew away the Blogger ID numbers. So now I have a bunch of Haloscan comments that are not tied to the correct posts anymore. I’m sure there’s probably some way to fix this, but I have neither the knowledge nor the desire to figure it out.
hmm, i could probably write a script that would go back and insert the blogger post_ids into your wordpress posts so you could run the import-haloscan script that i wrote. let me know if you’re interested.