FWIW, I'm one of the people who would buy one of the guest/lite/whatever accounts. I did have a paid DW account, but the only paid account feature I really care about is the ability to get copies of my own comments. The ability to track is important, but less so. Unless I decide to move my main journal activity over here, I won't become a regular paid member again, but frankly it bothers me A LOT not to get copies of my comments. Because of that, since I let my paid membership lag I've left almost no comments on DW.

I like Dreamwidth quite a bit, and I'd be happy to support the site with a smaller amount of money for the features I want to use, but I can't justify paying for full membership to both LJ and DW. I'd love to have a middle option. I don't know if this is something doable, but maybe to limit cannibalization of paid accounts you could put some activity limits on the lite accounts? Like, copies of comments up to x number/month, which would make it an unattractive option for people who really are making DW their main journaling/commenting platform.