ASP NET MVC provides jquery.validate.unobtrusive validation that, using jQuery validation, let us set validation attributes into model class.
http://weblogs.asp.net/mikaelsoderstrom/archive/2010/10/06/unobtrusive-validation-in-asp-net-mvc-3.aspx
Would be nice if it may work also with kendo ui validation.

Very hard to coloring the icon (only black and white if using sprites). I need to color the icon especially during validation when invalid. And second, I also want standardize icon in my project with glyphicons.

Support row templates in conjunction with frozen / locked columns

Looks are not enough... Performance please !!!


Besides reasonable funcitonality and good html5 looks we really need to start hinking about how to bring this to a new level of performance. Data's getting bigger and bigger but the charting tool hasnt up'ed their level in handleing that data. Please review and increase the cap of how many point a simple bar chart can handle...Example?
try plotting 4k points ( x axis being 0 or 1 and y axis jsut a count from 1 - 4k) using a bar chart. One of them might be reasonable but what if you have 5 of them or more on the same page ? 
Ambitious ? Stupid ? Not needed  ? probably because one doesn't need to deal with that kind of data, but I promise to any analyst that that day will come !!!

Add support for intellisense, auto-complete and syntax-highlighting to the editor. This enables the editor to be used for writing code or script. The intellisense and auto-complete rules should be customisable and support Ajax callbacks to populate.

Examples:
CodeMirror: http://codemirror.net
Brackets: https://github.com/adobe/brackets
Cloud9 Editor: http://ace.ajax.org

Since now Google started doing it on Gmail, I believe that we'll need even more these features.

Where several pie charts are displayed above each other, it would be nice to specify a consistent diameter or max width for the legend (when the legend is displayed to the side) to ensure all the pies line up together. Longer legend items then need to wrap.

When creating an element to make into a dropdown you can add the attribute 'required'. Instead of this it would be better if the external wrapper was made required so the browser has an element it can focus on, rather than erroring when the page is submitted and validated by the browser. 

It would be great if the chart control was able to produce a radar or spider chart, currently we have to use Silverlight to deliver this feature in our solutions. 

Many other libraries provide responsive widget like charts, graphs, Gantt charts, Tables and so on. For the widgets in Kendo that are not responsive, when will that happen?

Within the Grid you can currently either have single-row editing, or batch editing. However, batch editing does not necessarily show the end-user that the Grid is actually editable. In order to make the Grid more intuitive it would be great to have all cells display their edit template constantly to ensure that the client knows they can edit the component.

Additionally, sometimes a user will want to edit more than one row at a time, but not have the entire Grid in edit-mode. Being able to open several items to be edited at once would help with this user interaction.

This is why having multi-row edit, the ability to have multiple rows in edit-mode at once, would be a nice feature to have in a Grid. It would also theoretically open up the ability to have all rows in edit-mode at once.

 when i try to drag and drop the treeview nodes from top of the treeview to the bottom (last node) of the treeview,while dragging, the window does NOT scroll automatically.
Scroll bar should automatically scroll to the draging direction

I want specific column in Kendo UI grid canbe disable columnMenu! Now only can disable sortable and filterable but not the whole columnMenu~

It is possible to add commands to the toolbar. However, if you only need one or two commands (such as an "add record" button), this means wasted vertical space.

So I appreciated if Kendo supported the creation of additional commands in the Pageable Bar.

A Pluralsight Course or Telerik Video Training, building a real App with KendoUI Mobile and AngularJS in AppBuilder that shows MVVM, remote DataSources, SQL Storage on the device, BarcodeScanner, Analytics and Backend Services.

KendoUI has window widget, but it's too simple, I suggest just like jbox or artDialog.
jbox:http://kudystudio.com/jbox/
artDialog:http://www.planeart.cn/demo/artDialog/index.html

I think as we try to create more RIA with HTML5, having multi column dropdown is very intuitive 

Similar example:
http://demos.devexpress.com/aspxeditorsdemos/ASPxComboBox/LargeDataSource.aspx

The loading text of kendo.ui.progress is hard coded. 

Please make it localizable.

The currentTimeMarker property currently displays a time marker only on the Time Column of the scheduler. The typical behavior of most  calendars is that the marker spreads across the width of the entire calendar across all columns. It'll be nice if Kendo Scheduler could also support that.