QlikView = Guided Analytics
Qlik Sense = Self-service visualizations.
QlikView and Qlik Sense are both built on the same platform for associative data, selections, and governance. QlikView 11 is a robust solution for complex data.
Qlik Sense has new visualization features and a drag-and-drop experience using a library feature. There is also a new storytelling feature and responsive design that automatically changes depending on which device you are viewing the application on (tablet, phone, computer, etc.). It is easy to build apps right on your tablet! There are many other advantages, but these are just a few off the top of my head.
Why don't you download Qlik Sense for free and play around with it:http://www.qlik.com/us/explore/products/sense
Once you download it, you can view free training videos here: New to Qlik Sense Videos
Hope this helps!
The responsive interface is a big benefit.
The ease of use to build charts with little or no coding
Simpler licencing model
QlikView is the more mature product so lots of extra features in it that are currently unavailable in Qlik Sense but that's not to say they wont come into Sense in future. They are making regular releases all the time.
It depends on your current needs from a tool as to which product fits best.
You can share the qlik sense apps created with the FREE version of the Qlik Sense Desktop with others whereas Qlikview has restrictions on sharing documents, which is a big plus for Qlik Sense.
You only have 1 interface for Qlik Sense instead of using the IE plugin\Ajax interface with Qlikview.
If you don't require all the bells and whistles that QlikView has such as being able to create buttons, hiding objects and using objects such as containers to save space Qlik Sense is the way to go.