That sounds like the same as some of the other forums I use, and of course it would speed up the "joining experience" for any new registrations. If I'm honest, I was ok with your original method, I think I'd err on the side of not having to clear up the mess left after a spam attack.
Can you make the link point to a "please introduce yourself" thread at the same time ? I'm just thinking it might be one way to get new registrations over the initial hurdle of that first post.
Brian
Edit to add - hey, that "notify" button really works well, it's almost like a yahoo email group now ! Amazing the little things that keep me amused.....