I came across this very well rounded article on Lifestreaming that goes from providing a definition, to describing the personal advantages of creating one, and covering the benefits associated with the users who generate the data.
I think this is a great little primer on Lifestreaming that provides an excellent starting point for people who are interested in learning more.
Here’s a snippet
Added to this is the possibility of allowing subscribers to see the bigger picture of who you are online. Rather than just presenting them with links to articles and blog entries they can also see your other online activities, such as favourite You Tube videos, pictures and music. You will be presenting yourself as a rounded person rather than as someone simply tapping out those articles and blog entries.
I recommend you go read it as it does wrap up the concept very nicely.