Sometimes the OnClientClicked event is fired ony after the second tap, the first shows the peek template. Sometimes this can also be observed with the NavigateUrl. It is easiest seen when JS code is executed from the NavigateUrl, e.g.:  NavigateUrl="javascript:CDRequestMenu()"
This is related to the fact that there are no separate events on a touch device for mouseover, mousedown, click and mouseup.

Tap on a tile to execute its navigation or rather some JavaScript. Expected behavior is for the click event to fire. Actual result is that the tile's drag is initiated - the DragStart event on the tilelist fires and the tile gets the big z-index, and you can drag it around. This behavior does not manifest when there is only one tilegroup.
Setting EnableDragAndDrop to false will alleviate this, but will remove the drag-and-drop functionality.

Currently alt="" for the images and such a property will let the developers improve the accessibility of their pages.

RadTileList currently has the EnableDragAndDrop behavior but no way to react to these events.

Also, add RadTileList to the category list in the feedback portal

Currently the mouse wheel scrolls a fixed amount of pixels. A property should allow the developer to control this speed. Leave your comments below on the way this property should be implemented (e.g. an enum or an integer from a given range).

Add loading data on scrolling instead of loading all data at once?  Similar to the way Pinterest loads data on scrolling.

Setting the CssClass property of a tile does not transfer the custom class attribute to the rendered markup. This means that custom classed cannot be used to create a cascade and style concrete tiles.

A postback occurs from the button, but its postback events are not raised (the Click event handler for the button)

<telerik:RadIconTile ImageUrl="./images/info_icon.png" NavigateUrl="./add_loading_sign.aspx"></telerik:RadIconTile>

works,

<telerik:RadIconTile ImageUrl="~/images/info_icon.png" NavigateUrl="~/add_loading_sign.aspx"></telerik:RadIconTile>

Does not work, but it should.