Those arriving at WordPress.com front page are either from other blogs hosted on WordPress.com or search engines, and most of them are interested in creating a blog for themselves. Those who want to explore featured posts are mostly the existing users. Therefore, I suggest to:
- make the sign-up area more prominent, and
- featured posts more easy to scan.
Here is a greyscale mock-up of what I mean with the first suggestion:
What do you think?