If you accompany each update of, for example, squeezed books, with a learning from the last time you posted, then people will vote it up.
I posted here asking for feedback with my site twice, fifteen days apart, and nobody questioned whether I should do this. I think news.yc is inclusive as is.
One of the things about having a tab is that the launch announcements would stick around there a little bit longer.
Perhaps this would also make the site feel that much more 'inclusive' of those who aren't in the YC program (and may have no intentions of attempting to participate), which was a request a while back.
Just a random idea.
(You expect people to post their startups on a separate page, when you won't use the one for feature requests?)
Is it intended as some kind of intelligence test on your users? In the same way as not explaining the markup system anywhere? If so, I think it's a silly test, and one your users are happy to fail.
If you haven't got the time to concoct some text, here's a suggestion:
Submit a URL with a well-thought through title to explain its relevance to your audience. Leaving the URL empty will submit a question for discussion. Please ensure submissions are relevant to Startup News; if you want Slashdot, Digg, or Reddit, you know where to find them. There's a thread for Feature Requests, so please add a post to that and refrain from starting anymore "Vote up for ..." threads. There's a bookmarklet to ease submitting, but it doesn't mean these guidelines don't apply.
We shouldn't have to Google for this page?:
"feature requests" site:news.ycombinator.com yields: http://news.ycombinator.com/item?id=363
PS. Feature request: "search"? :) It seems a few people agree: http://news.ycombinator.com/item?id=363