Microsoft's article in its official blog describes some of the new features that enhance developer productivity in vs 2013. The article said: "In vs 2013, we introduced new features that saved time working in the editor and increased productivity." These new features and some of the most popular productivity toolset come from the enthusiastic feedback of users through user voice requests, forum posts, and connect bugs. The MVP community has also helped us make the selection.
When coding, you can easily view the inline (definitions inline) with Peek definition in the editor editor without having to open a new document tab. All you ask for is to click on the correct symbol, click Peek Definition, or press ALT+F12.
Visual Studio 2013 also has an enhanced scroll bar that provides visual cues when scrolling vertically.
Microsoft has also deployed new navigation (Navigate to), allowing the user to type any part of a symbol and find its definition (using Intelligent semantic search). The new parentheses integrity feature (auto brace complete feature) automatically adds closing parenthesis, quotes, parentheses, and square brackets.
Complete list of all new features of Visual Studio: http://msdn.microsoft.com/en-us/library/bb386063 (v=vs.120). aspx