Again, how many new users want to start a new thread? The answer is obviously here on the forum, but by asking I'm hoping someone else will look
If we had a Say Hello thread, most legitimate posters wouldn't even notice they couldn't start a new thread - they'd just be settling in and saying hello with their first posts.
I don't like Newbie threads personally - pages and pages of people you'll never see again saying inane things. Or worse - if you are a lurker on a site, being asked to "Step by and say something about yourself first!" when you have a legitimate comment on an existing post.
But it does act as a containment chamber - you don't have to hang out there unless you want to after all.
And perhaps we can spank new users into using things like capital letters. Not mentioning any names.