I am put off using KendoUI because of the limiting nature of theming and styling the controls especially the sprites They don't scale well, can't be coloured and are hard to replace without lots of css editing.
This is not completed in Kendo UI Web. I cannot use Font Awesome for the sort, filter, menu icons in the grid column headers. I do not want to use a command column for this.
This is not completed, because it has only been added to kendo UI Mobile and not vanilla Kendo UI.
UPDATE: Support for font icons has been added to Kendo UI Mobile, and will be enabled by default for Opera, IE10, and BBOS 7. This is be part of the November 2012 release. -- Thanks for the suggestion! This is a good idea. We'll evaluate it for a future release.
This can be done already if you are prepared to tweak a little the default font-awesome css file your self :)
Additionally, every theme you have uses the same icon set. Really, the themes are just some simple color changes. Along the same line as this question - themes should also change icon sets (maybe telerik provided or other icon sets). Like Telerik MVC Extensions has different icons for the grids and such - why not let uses select one of those icon sets with any theme.
We too have run into the limitations of Kendo (and Telerik MVC) icon sprites. Very interesting idea, however we would prefer the ability to switch to FontAwesome icons (or other icon sets) for one application rather than completely switching - probably other solutions have other limitations if they are the only choice. Anyway it would be very welcome to be able to use existing large icon sets to get consistent look and feel across the entire webpage rather than only across Kendo components!