Add an beforeOnchange event that fires to allow additional validation before the change occurs. If returns false then onChange never is fired.

If you export your grid to Excel then you may have noticed that sometimes the columns are smaller than their content.
What I mean is, I have double click the coumn header in Excel to get the desired "auto-width".
It would be nice to have this functionality already in Telerik.
So that the column width perfectly fits its content.

kendo grid dynamic does not contain a definition for MinResizableWidth throwing this error on resize column ..multiple dynamic gids in my mvc view 

minResizableWidth float
The pixel screen width below which the user will not be able to resize the column via the UI.

Bug: Column Resize Handle not showing on dynamic Grid Columns

The problems are the hidden columns. If you have a hidden column in the grid, you can't resize all other columns after the hidden column. That is a very nasty bug, so please Kendo-UI team make a fix for it.

The Grid should be able to easly navigate from rows with the keyboard, and also select them by enter.

Allow users to filter with null values

Right now kendo's system for alternating rows is to specify rowTemplate and altRowTemplate.  For any non-trivial row template, this makes for a big ugly DRY violation as you copypaste the entire template just to give it a different css class and leave it otherwise identical.  Any future changes to the template have to be made to both copies, and any potential template issues have to be tested on both even and odd numbered rows.

If rowTemplate received whether it's an alternate row as a template parameter, it would be easy to do common things on alternating rows without ever needing to define altRowTemplate.

Virtual scrolling does not work for big datasets in IE and Firefox. We need adaptive scrolling 
http://stackoverflow.com/questions/2402953/javascript-data-grid-for-millions-of-rows

optional clearFilters button to grids toolbar

Right now columnMenu is available in each column, along with that, it would be better if there is a centralised option where user can configure the columns.

I have a column that contains a checkbox and I would like to be able to prevent it from reordering, similar than sortable or groupable, that not all the columns can be sorted or grouped.

Thanks.

Please implement multi-row drag-and-drop in the Grid widget.

In your grid demos titled "binding to remote data" filter for column ship city when i choose operator does not contain operator and fill "Rio" value kendo grid sends empty filter GET parameter. I have observed similar bevavior in my project.

Add Shift+Space support in Grid to select contiguous rows using keyboard navigation. Currently, if the user wants to select 50 contiguous rows using the keyboard, he/she needs to hit Ctrl+Space 50 times.

Grouping row in grid can expand/collapse after click on any area on the row not only after click on plus/minus icon. This behavior is similar to checkbox in browser with label for attribute

Multiple String searching in standard filter.

Today the basic Grid filter for strings can be used to search for 1 or 2 items at best.  It would be great to be able to filter for > 2 items from 1 column at a time.  

A multicheck box filter does not work so well when you have 100k+ items, and the multicheckbox ends up with 1000s of items in it.  A string search is more appropriate for the end user.

Our current grid a user can filter for upwards of 500 strings of text in one column by treating the input as a textarea that is styled to auto-grow and is not resizable.

Give the developer an option to show a search field in the grid. This option should be configurable so we could chose which column(s) to search in. With a single keyword the user would be able to get a specific row.

In lieu or as part of select-all capability:

Expose a way to retrieve the filtered set of data (or keys) in the grid and other filterable controls.

In other words, when a user has applied their own filters, there is currently no method to retrieve the filtered set across the entire dataset. That makes implementing a select-all button a bit tricky as you have to either select all on the current page (view) or the entire unfiltered dataset and then apply the filter yourself.

Pressing <Enter> should save grid row edited in-line by default, even if it has a sub-grid. Currently, if a grid row does not have a sub-grid, pressing <Enter> saves it when edited in-line, but if it has a sub-grid, that sub-grid gets expanded instead. I think, this is a non-standard behaviour (can be set by specifying some new option, but not by default). If my suggestion will be implemented, it will allow to speed up data entry, because if user types in some text in a text box, it is easier and faster for him to press <Enter> rather that switch to the use of mouse.

Also, pressing <Esc> cancels editing in any case (with sub-grid or without), which is correct.

The pager drop down page selector is too large and obscures other controls and the bottom of the pager frame.

I hope this observation is useful.

I have a screenshot but there is no facility here to post it.