How to assign a keyboard shortcut to a specific New Window template in Terminal.app?

Solution 1:

Open Automator, create a new Service with the following Run AppleScript action (no input):

tell application "Terminal"
    activate # switch to Terminal, launch if necessary
    tell application "System Events"
        keystroke "t" using command down # open a new tab
    end tell
    set current settings of selected tab of front window to first settings set whose name is "MyTemplate" # switch settings to your template
end tell

The service will be accessible from the Services menu, and you can assign a shortcut in System Preferences » Keyboard » Keyboard Shortcuts » Services

Edited to add: You can specify whether you want this service to work globally by specifying any application or Terminal in Automator. Both work with this code, it just determined in which applications the service shows up.

Solution 2:

You could save a setup into .term file and then use a third party launcher (Quicksilver?) to start it from there.