http://stackexchange.com/ went through a major change somewhere between June 11th and June 12th according to the Wayback Machine.
This is how it looked like before, with focus on the sites/communities and many links from the homepage itself. After the change, the homepage is showing only the list of Hot Network Questions, sorted by hotness points (can be seen as tooltip) and for anonymous visitors (i.e. those not logged in) also showing a nice "Stack Exchange Q&A communities are different. Here's how" banner on top.
So the focus changed drastically from sites to questions, and all links removed, making it cleaner.
I am not challenging the change, just curious to know the reasoning behind it, what motivated such a change, and whether it's successful or not e.g. more incoming traffic from the portal to sites needing traffic?
Worth to mention, this new design is very similar to the first design of the portal (since Stack Exchange 2.0 was declared) as can be seen here.