There are two important groups of users: 1) first-time visitors, and 2) everyday visitors. Your suggestion improves the site for the former, but you should think about the latter too.

As a everyday visitor, I want the things important for me to be at the top of the page, so that I do not have to scroll down every time. On the other hand, the things important for me can have a small font and no graphics, because I already know what to look for. What are things important for an everyday visitor? Simply: what has changed since yesterday -- new articles, new Overcoming Bias articles, new comments, new wiki edits (not everything is important to everyone, but these are the frequent changes), and perhaps featured articles. These things are not high enough now, neither are they high enough in your proposal.

After these things (which compressed enough should still leave 2/3 of the top screen empty), there can go your brain graphics, short description of the site, and the meetup map -- things that should catch the eye of the first-time visitor.

The essence is -- think about different types of users and their needs. You did it for the new users, now think about old users too. On the title page, having to scroll down is bad. Scrolling down is OK only when reading a longer text, which must begin on the first screen, but may continue below.