I sent this to the email on the developer website, but it bounced so I'm posting it here:
First of all I wanted to thank you for the awesome custom post type switching plugin. It seems to switch the post types fine.
I did run into some trouble though - it doesn't seem to maintain the meta data. I switched a post and then when I looked at the post page it didn't display any of the custom field information.
I thought maybe it was just not displaying it with the new post type, yet when I switched it back, it didn't seem to have it anymore!
I'm not sure if this is a known issue or not, but I figured I'd let you know.
Also, assuming that can be fixed, I was wondering if there was a way to make it so the change could be done from the bulk edit area. It would be great to be able to do so, since I have thousands of posts that need to be resorted.
Thanks again for your work!