You mean this?

http://news.ycombinator.com/rss

Link at the bottom of main page.

You and I (and now aykall) certainly know that the link is there, but it's needlessly non-standard UI.

User Interfaces are best when people get what they expect, and they don't need to overthink what they're doing.

In this case, it means that news.yc probably SHOULD support Feed Autodiscovery, by having link rel="alternate" specified, so firefox and other browsers put the easy to see RSS button on the corner.

Is it necessary? Of course not. But if a user is trying to stay abreast of what goes on on your site, it's usually better to give them what they expect.

Is there just the one feed for the whole site, or are there user and per-article comment feeds and a newest article feed somewhere non-obvious?

Checkout Feedity - http://feedity.com for creating custom RSS feeds from any webpage

(Shameless self promo)