From the Hacker News Guidelines: http://ycombinator.com/newsguidelines.html

Under "What to Submit": "On-Topic: Anything that good hackers would find interesting. That includes more than hacking and startups. If you had to reduce it to a sentence, the answer might be: anything that gratifies one's intellectual curiosity."

Since it's being upvoted, then I guess it's gratifying enough people's intellectual curiosity.