Code Simple Two Column Dropdown Menu

Need a Coder to implement a Pre-Designed Drop-down menu onto this site: [login to view URL] where the "Blog" button is on the navigation will now say "Categories" and if the user HOVERS over the button it will drop-down to reveal 2 columns of categories... The menu should AUTOMATICALLY update when I add a new category to the backend in Wordpress... There is a function to call all of the categories into the menu. Should be Cross-Browser Compatable and FAST LOADING. Design Example is Attached. Here is an example of how it should work: [login to view URL] PLEASE ASK QUESTIONS IF YOU ARE UNSURE OF ANYTHING!