In addition to basic Line and Area chart types, it would be great to add support for the Step Line and Step Area chart type.
Examples: 
http://www.infragistics.com/products/jquery/sample/chart/style-chart-with-themes (switch Series Type to Step Line and Step Area)
or http://www.highcharts.com/stock/demo/step-line

Native mobile controls can show small clear icon which is shown only when something is typed in the input control (see address bar or search bar in iOS). Some sites (e.g. google.com) also implement this behavior.
Please add this behavior to Kendo input controls. For example, it can be activated by data-clearable attribute or something like this.

Ability to have a hidden menu that slides in or pops in much like the other apps and frameworks have.

Allow parameters to be passed to Actionsheet callback functions.  I have a need for a varying number of Actionsheet actions based on data-driven settings.  I can dynamically populate the Actionsheet with jscript, but each action has to call a different callback function.  What I'd rather do is have each action call the same callback function and just pass an ID of the selected option to that function.  For example, I am using the ActionSheet to present the user with a list of places they can route the current record.  I don't need a different function for each place they can route it - just the ID of their selection.

Currently templates are only supported when the DropDownList is in an open state.  Ideally, the DropDownList should have the ability to display a template when in a closed (selected) state as well.

A common use case is to display icons next to the dataTextField.  However in it's current state, when an item is selected the icon is no longer able to be displayed.

In window widget I create links and buttons. On pc system it's work correct. But on mobile devices (just like iPad or Nexus 7), these click events is so hard to touch. Other click events outside the window widget is easy to click(the same links or the same buttons).

Allow pinch to zoom images to start zoomed out.  The "pinch to zoom" feature demonstrated at  http://demos.kendoui.com/mobile/view/zoomable.html is useless for most practical applications.  Go to the camera app on your phone and look at photos you took - they start zoomed out and then you can zoom in on them if desired.  If you had to zoom each one out to look at it, that would be incredibly obnoxious.

Add support for drawing box plots (aka box-and-hiskers).  Include capability to display outliers.

When the grid is refreshed with grid.refresh(), regrouping and resorting is not done automatically; as a result, any updates to the underlying dataItems that affect sorting or grouping are not reflected in the grid. That level of control should be available to the developer. Therefore, I would like to suggest that the grid.refresh() method accept an optional configuration object:

var options
 = { resort: true|false (default), regroup : true|false (default)}
grid.refresh( options )

In this way, if the grid is groupede by [department] for example, and the [department] of certain rows is changed programmatically via dataItem["department"] = somethingDifferent, when the grid.refresh ({regroup: true}) method is invoked with the optional argument, the grid would be regrouped, reflecting those changes to the rows' dataItems.

This bug is visible in your demo at http://demos.kendoui.com/web/grid/editing.html.

When using a scrollable, editable grid in IE (9 or below):
•	Scroll down so that the first row of the grid is no longer visible.
•	Click on any row.
•	The grid jumps back up to the original "unscrolled" position. (In your demo, on my screen, this means that only the first 10 rows are visible.)
The result is that I am unable to edit any row outside the first 10, unless I use the keyboard to navigate.
This does not occur in Firefox, Chrome, Opera, or Safari - only in IE.

I believe TabStrip is not supported with SplitView as SplitView can not be used in a view. This is inconsistent if the application needs a common TabStrip across all pages.

Attribute binding is how MVVM should be implemented but currently the following limitations have forced me back to widget-binding ...

1. Some data attributes are not supported (eg. grid "autoBind")
2. Attributes cannot refer to external templates and these must be defined inline.
3. Line breaks are not supported making long inline definitions hard to read and code.

I suggest attribute binding (and documentation) is developed in parallel with widget binding.

http://www.kendoui.com/forums/dataviz/chart/support-for-chart-types.aspx

Any update on this?

Fix issued described in support ticket 634770 

Sorting accented characters currently is not supported out-of-the-box and we must use ServerSorting to be able to custom sort the items and send them to the Grid. 

The grid should sort accented characters directly on the client. 

I'm using the MVC wrappers, I have a foreign key column in my grid and I use the standard foreignkey editor-template. It is not possible to bind a null value (foreign key not set) to the dropdown. It works when I change the template and replace the kendo dropdown with the standard mvc dropdown.
So I guess there's a problem with null values on the kendo dropdown

If I use text method for changing the text of a node in a treeview, the icon gets removed. Same happens if the dataSource is an observableHierarchy object and I use set("text", newText).

Placeholder is supported for numeric text boxes, it would be nice if placeholder could also be supporter for all text box input, i.e. plain text.