I would like to be able to use external protocols like the steam:// URL to launch games from steam, IRC:// so I can use IRC links etc. Currently the implementation is restricted to web addresses.
Reasons: The handlers for these protocols are installed by me, thus approved more than likely. I need to click on it, which is nothing more than a spam email or link to a file to infect my machine. This is likely more secure than the web browser links because they are not handled by default and would require the end user to go out of their way to have them handled.