Please add a cell Name field visible on the client and server side. If this name could be grabbed from an excel spreadsheet using the naming functionality built into excel, that would be a major plus.

The spreadsheet adjusts the width based on how many toolbar items are available.  The width property doesn't help. It would be nice to have the spreadsheet list of tools to collapse if a width is specified that is smaller than the toolbar row at the top.  I don't always want the spreadsheet to be the same width as the tools that are available.

The Spreadsheet control looks fantastic and will help us replace existing functionality, along with building new streamlined user interfaces.

Please include the ability to specify individual cells that function as drop-downs, where we could bind the data to an external source and have the user select one of the options.

Please provide the ability to specify splitter type of functionality where several rows could be static while the remainder of the screen would scroll.

I would like to see the ability to add checkboxes to spreadsheet cells.  In particular, I would like to check boxes in the top row and/or the right column to select rows or columns and then modify cell values based on the the selected checkboxes. 

Can be interesting the power pivot functionality to be supported for spreadsheet control for telerik ui for Ajax.Net.