I'd love it if you would consider making a real office document editor for the web. Take a look at this editor from OnlyOffice which they use in their CRM system:

https://personal.teamlab.com

It's built on HTML5 and the canvas element. The way you get complete control of every pixel and can make a desktop-like editor is simply stunning! This must surely be something Telerik also considers? There simply is no comparison to a normal HTML 4 editor which fails at such basic features as header/footer.