Going beyond a fresh coat of paint, the new site is part of a long-term effort to unify all the products and resources in their ecosystem so they are easier to use and discover.
The Unreal Engine landing page has been significantly reworked and features a lot more useful links and information than before. Unreal documentation has all been migrated to the Epic Developer Community, which means you can now search the docs, tutorials, and forums all in one place.
Read the official announcement to learn more.