When (root) desktop window is selected, pressing, for ex., the 'a' key would select the first icon having its name begining with 'a'. Pressing enter would then execute it (ie: if it's a link, execute it, if it's a volume, open it,...)
If there are more than one item having its name beginning with 'a', pressing 'a' again would select the next one... and so on...
Plus: when an item is selected, arrow keys may be used to move onto the desktop grid...