Just test the basic usage sample on the web site.
If you are able to set all splitters as you wish, you are the king!
All other controls work as expected.

Please allow for the creation of custom UI widgets and plugins that can be tied closely with the rest of the framework similar to how jQuery plugins work but better ;)

Start off by providing good documentation of the different classes (both JS and CSS) that developers can and should use and provide guidelines for writing custom code so third party controls and extensions follow similar style (visually and programatically).

Also adding a Kendo Marketplace or something like this where developers can publish their plugins and other can vote/comment on them would be great for everyone. 

jQuery UI and the plugins that are available there are great but I think Kendo UI and the Kendo community can do better especially if we set the bar a little higher from the get go.

If it is at all possible, please implement drag & drop inside the grid to enable users who need to manually sort items in order of importance (for instance a list of books I they wish to show in certain order).

Element to chose color. That is usefull forvisual  template bulders and CSS editors and more. I am curently needing this UI

http://www.kendoui.com/forums/integration/integration/kendo-ui-requirejs.aspx

http://www.requirejs.org/ might be a good fit.

handle RTL support in this awesome package. We really need such feature for using this library in our RTL-Language-Based Clients' projects.

Would be nice to have helper/wrappers for KendoUI for ASP.NET MVC 3

Having the ability to create "right mouse click" context menus would be very nice. 

Hi,

The combobox and autocomplete are ok - but I think the usability and functionality could be dramatically be improved with better filtering, support for option groups and support for multi-select.

Can you please enhance the these controls to behave more like the Chosen dropdown control?

http://harvesthq.github.com/chosen/


Thanks,
Glenn

Hello.
Congrats for this amazing framework to all webdev..
I was searching in the demo some features like forms (contact, validations fields, etc), but i cant see it.
is there some forms html5 based to start with kendo ui ?

thanks a lot!

Add extensions for templating engines such as JADE, HAML, or JQuery Templates, so Kendo UI can be built from VIEW files in MVC frameworks such as Express or Kanso on NodeJS.

Enhance the window functionality with minimise and maximise buttons. 

Something similar to the following site (which also has some other useful functionality.)
http://jsbin.com/ajuwa/19

Tooltips which can be attached to elements to provide additional information on hover.
Could either be taken from the title attribute, a string or a specified element.

Can provide additional styling and interactions going beyond the current restrictions of browsers title hover.

For example, an anchor tag placed in a grid table cell is not currently rendered as HTML - instead it is displayed as text.

Really important to have support for ARIA roles on these types of widgets. That's what they were made for, and jQueryUI does a pretty good job at this.

Accessibility is important.

For example, when the autocomplete list appears or disappears, the entire page flickers to black for an instant. This happens roughly 50% of the time for me. I disabled all my extensions and that didn't help.