2. I host a single node for my blog. Both entries and comments get published to the node, and an item can be an entry or a comment. This requires some syntax in the payload format to differentiate entries from comments (e.g., it can't be plain Atom).
This is the easiest to implement, but shifts some responsibility to clients to parse whether it is not only a "blog"-like message (based on the node), but also to parse the actual message and find out whether it is an entry or a comment. Looks like we could use SIOC here. Entries and comments can be published either to single node or individual nodes. SIOC links it all together and builds Entries/comments trees. Web page with blog post could be linked (via "meta" tag?) both to SIOC representation and to Pub/Sub node where updates will be posted. It could be either node only for this entry or for all entries in blog. It does not matter in case of SIOC items.
