Morbus Iff comments on the Subscriptions Harmonizer and brings up good points about using OPML as the transfer formats.
This just focuses on the aggregator possibilities, and doesn’t consider OPML sniffers that could create blog “six-degree” communities (based on XML, as opposed to scraping blogroll HTML).
Is there a standard convention for linking to your site’s blogroll and/or subscriptions list? I’ve seen some discussion about this but need to dig a little further. In my case my blogroll and subscriptions list are the same, but I can see where they might be different.