It would be a great help if there was a way to add a Trendline to a line chart in the DataViz collection.  This function is available in excel and other similar programs.  
The wiki page explains:
http://en.wikipedia.org/wiki/Trend_line_%28technical_analysis%29

Is there some way to flash(refresh) one of the nodes in the "TreeView" widgets?

And how can I change the attr of the node easily?

kendo will be more beautiful if kendo add a scrollbar plugin, and use it in some other widgets(DropDownList, MultiSelect, and so on); and I find something that I think it's not pretty: the grid widgets in metro theme, when I click the head of the grid, the order icon is not display immediately.

Currently if you drag weekly event from Tuesday to Wednesday for example and change to edit series it is not being changed to Wednesday. It stays on Tuesday. I think most of people would expect it to be rescheduled for Wednesday.

Chrome displays a vertical scrollbar for all kendo window using iframe. Example:
http://jsfiddle.net/Vz2Z4/

I'm creating a FAQ for a client and I need the Question and Answers to be collabsable inside a listview but I also need to filter the list by keyword...  

I would like something similar to the Collapsible Lists in jQuery Mobile:  http://jquerymobile.com/demos/1.2.0/docs/lists/lists-collapsible.html 

Please add generic versions of DataSource and ObservableArray to the TypeScript definitions file.

accordion widget is missing. please add it

Add the RadRadialMenu from the Win8 controls to Kendo UI

You can currently build a pie chart and display the value of each section of the pie by using a template on the label and the #= value #.  It would be nice if we could do something similar to this in the title or somewhere on the graph where we could display the sum of all of the values that are displayed in the graph.  It would also be nice if this could dynamically update when one particular item is filtered

If we have a flow of 3 steps. A1 -> A2 -> A3 -> B1 I want to be able to hit back and go to A1. This is currently not allowed and we must construct flows based upon views that have to be linear forward and back. I want to be linear forward but go back differently.

line 26486 
has this:
data = extend({}, { field: group.field, value: group.value }, group.aggregates[group.field]),
should be this:
data = extend({}, { field: group.field, value: (typeof(group.value) === 'undefined' ? null : group.value) }, group.aggregates[group.field]),
Or something like that.  In any case, without that change, the following will blow up when cell value is undefined.
groupHeaderTemplate: "#=value#"

Setup: 
* KendoUI Community Edition v2013.2.716
* Multiple resources in event

When Field in Event contains Array of guids - it shows fine in the event, but on grouping throws an error (as guids are treated incorrectly in filtering function)
When guid is wrapped by '', then grouping works well, but Event do not show assigned resources...
Using debugging I found that problem is in filtering (Piece from the code): for(r=a.filterExpr(e),s=r.fields,d=r.operators,o=c=Function("d, __f, __o","return "+r.expression),(s.length||d.length)&&(c=function(e){return o(e,s,d)}) 

Problem:
the same CSS classes are used for styling of different widgets, hence when they nest, styles interfere.

Example:
MultiSelect in a Grid column filter. The filter form is placed in the column menu and menu item styling (.k-filter-menu .k-button) is propagated to all k-buttons in it, including MultiSelect's selected item tags that are also k-buttons and have styling with lower specificity.

Solution:
Use additional CSS classes for specific styling. That is .k-button is Ok for generic styling (color, border, hovers), and another, say .k-item-tag and .k-menu-item, for widget specific (margin, width etc.)

Would like to have a splitter in mobile controls.

There is no pure HTML5+JS equivalent for RadSpell available anywhere that I can find. We currently use RadSpell but are trying to move away from WebForms. RadSpell is holding us back.

At the moment, Kendo mobile is pretty 'static': you need to define labels, etc. for switches at the point of construction.

This makes internationalisation a little tedious, as to change the label for a different user selected language, we have to 'manually' use jquery to dig out the span, etc.

It also means that whilst we can get it working as mentioned above, any update to the toolkit could break our code as we are building in expectations on html structure.

Further, aside from label setting, 'containers' need to adjust their sizing to accommodate the dynamic content, e.g. switch is a good example of static!

If I only have 3 items in a grid then it should only be as tall as it needs to be to show them, but if I have 100 items then I want it to be tall enough for 10 items or for say 300 pixels and turn on scrolling. If it's shorter than the threshold I don't want the scrollbar shown at all.

A quarter is not the same as 3 months in the same way that a week is not the same as 7 days. Feb-Mar-Apr is not a standard quarter. Kendo automatically lines weeks up on Sundays. Please consider doing something similar for quarters.