conditional logic - e.g., hide if empty fields

It would be great if we had the ability to insert simple conditions in the "layout" section of each form. For example, for a field called "color", the following code in the layout template would hide it if it was not entered by the user: {if color}Your color is {color}{/if}.

I've seen similar things done with CCKs that use the Smarty template system. If Smarty were used, administrators would have a wide array of options to configure the template without using overrides.