Personalized Blog Views

John Battelle started an interesting thread on "merhandising blogs". In my understanding he suggests that blog engines could provide tools for blog authors such that referal information of blog visitors could be used to personalize the view of the blog. E.g. when a blog visitor enters the blog after having done a search for "car radio's", the user would not only be directed immediately to the relevant blog topic, but sidebars would also list topics related to cars or radios etc.
I think that it could be interesting to personalize blog views for the visitor in general. I.e. not only using referal information about the visitor, but any information that is available. Blogs are a good example of sites where using the visitors personality is useful.