Well, the hacker news feature a lot of programming-related stuff that is certainly 'above' the (average) blog post level (in the whole blogosphere). I know of no better meta-filter than hacker news for blog entries attracting a hacker's mindset. Certainly, the appreciation for mathematical thinking as well as mathematical methods plays a big role in this (analytic) mind set.
While the novice programmer might not get (the content and purpose of) python vs. ruby comparisons and the like, readers with a weak background in math will not find this probability entry useful (or too 'difficult').
However, for a certain subset of all hacker news readers, which are looking to dig deeper, it is a very nice resource.
Hacker news, to me, is especially useful since it provides links which are well distributed in terms of this 'entry level'.
The problem was not 'is this appropriate for HN' but 'the title is wildly misleading'.
I agree that this is of great value to HN, and especially to me.
Yes. I think this exceeds the capacity of the blog medium.
I don't, it's just not for the lay audience.
I was able to read only part 1: Foundations, and these are my impressions. Definitely goes into my Bookmarks, so that I can read the rest...
Edit: The title was changed from "Probability Theory 101 (by Fields medallist Terry Tao)".