I'm still testing out these Google Sites updates. However, in the interest of keeping you all informed on the current build of Google Sites, I am posting the updates for you now.
Improved accessibility, editing and ease of use in Google Sites
Several accessibility improvements have been made to Google Sites, ranging from new keyboard shortcuts for editors (like Alt+Shift+F for opening the editor toolbar) to better viewing experiences for readers. Editors can now also set image width to 100% of the screen width and easily customize the font, color, and size of lower-level headers (H2, H3, and H4 tags).*
Enhanced integration between Google Sites and other products
Today we launched several features aimed at improving integration between Google Sites and other products. When sharing on social media sites, Google Sites now will showcase images in posts. You’ll see this change when you share Sites links on Google+ and other sites. Google Analytics support on Sites has been improved to support Universal analytics. Finally, Sites can now embed Google Maps Engine Lite, so custom maps you have created can be shared side-by-side with your content.