When is out of date, out of date?

A couple of days ago I was exploring a link to a wiki created by a class in New Zealand. It was posted to a mailing list to illustrate a good example of educational use of a wiki. And it was an excellent, genuine example. However as I was reading it, I noticed that the last entry was posted in about June 2007. My immediate reaction and consequent action was to stop reading and to move onto something else. Why?
When I thought about this, I realised that the more I read information and ideas on the web, the more I expect the posts, or entries to be 'fresh'. Why, I wonder. I would have no qualms about reading a non-fiction textbook that might have been published 10 0r even 20 years ago. What is different about the web?
Speed is also a need. I find that often I'll read something and if it doesn't 'grab' me, I'll either move on or at the very most, tag it and then move on.
I wonder what it says about me as a consumer? I wonder what this need for immediacy or action might say about our students as consumers?