I mean, robots.txt wasn't a "search engine" thing, it was a "robots" thing. Blocking the news UA doesn't really affect what gets crawled, Google doesn't generally double crawl pages anyway since that would waste your and our bandwidth. This is more of an indexing thing. I just find it confusing - which is not to say it's a bad idea. I'd argue the reverse, it's definitely way more useful than not. - Greg Grothaus

I Agree. Of course there's a not so well known 'noindex' directive for robots.txt that Google obeys for ages now. - Sebastian