Hey Everyone,
You've all expressed an interest in having Conditional Logic added as a feature for forms. Unfortunately this is not yet a native feature, however I took the liberty of working out a JavaScript method that you can use to add Conditional Logic to your forms. There's a tutorial to help you get started on our blog:
http://blog.clickdimensions.com/2015/08/conditional-logic-form.html
If you have anymore questions or need help with your applying this method to your forms feel free to post your questions in the forum with Conditional Logic somewhere in the title.
Hope this helps!