What I'm readingtoday on many blogs and IT News site is that Google will add support for the rel="nofollow" attribute on links.
The idea under this attribute is that when a search engine will see a link marked with this tag (something like <a href="http://www.microsoft.com/” rel="nofollow">Microsoft</a>), it will deny PageRank calculation on the submitted link content. So, if a Blog engine will place a rel="nofollow" attribute to all links on comments and feedbacks body, the submitted links will not be registered from the search engines and will not be used to calculate PageRanks.
This is surely an interesting idea but when I read that this could be a good way to fight the Blog Spamming phenomenon I can't stop laughing... 
I don't think so and my reasons are mainly these:
- Every Blog engines must be rewritten or adapted to perform the link signature with the "nofollow" attribute.
- If a Blog engine will implement this feature, who will have advantages? I think only the search engine (that will ignore the posted links) but not the blog (spam comments will be readable on the feedback section).
- If all the Blog links on every Blog engines will be targeted as "nofollow", this is not equals to the end of spam. A spam bot could continue to post spam comments again... ok, they will not be indexed by the search engines, but can you imagine the noise for the blog owner? He will have to continuously delete the spam comments and I'm sure that everyone of you that have a Blog and receives spam every day, when you have to delete it, the last thing you are thinking are the Google PageRanks!
With this post I don't want to say that this idea is not good but only that this is not the key to avoid blog spamming. Maybe it could reduce the spamming activities and move their direction to other placed different than Blogs, but the phenomenon will not be stopped.