In theory, all you want, and all that would be needed, is to keep the comments associated with the published link.
But how would that work? I can see two options.
The comment could be kept locally on eMule and whenever someone looked for the published file, the other client could contact the first to request the comments. The problem is, this would create a staggering increase in traffic. If you wanted to make searches on the comments, that would lead to a huge blow to the search speed.
On the other hand, the comments could go as a part of the publishing process and be kept on the servers. That would speed things up a bit, even if you wanted to do searches on comments, and diminish the increase in traffic, but you can't keep information on the servers. That's the whole point of this network.
In any case, there would be too much data moving around. I can't imagine what would happen to the network.
I don't know if I understood how this works but, the way it is, the comment is only sent, and in the same way as the file, after the request for the file, correct? That isn't perfect because it doesn't allow for comment comparison and to have access to the comment you have to start the download, but I think that it's all that can be done.
-- Edit --
I keep finding reasons to have and reasons not to have comments. What problems it would entail and solutions to those problems.
Although I would normally still think they are unnecessary, in another discussion I am seeing fake servers are starting to be an issue. Fake files might follow.
The question is, would comments really eliminate or significantly diminish that problem? It's a two edged sword, if you think about it, and you can see it might worsen the problem if you understand completely how it would work.
This post has been edited by Omnithec: 10 February 2012 - 08:16 PM