The update offers enhanced displays for higher resolution models. Under search, you will be able to view your recently viewed and bookmarked apps. And the update brings support for future form factors (like the Passport, no doubt), along with enhancements to search. And there will be a micro-carousel update on content home pages.
The actual version of BlackBerry World that the update takes us to is v18.104.22.168. Hard to believe, but when the store first launched on April Fools' Day 2009, it contained only 234 apps initially.