Overriding page.tpl.php for a menu_hook page
You wouldn't need node- at the beginning of your template file name as your path isn't a node page. Going off the Drupal 7 Theme Hook Suggestions, the file should be called:

page--announce_your_new_products.tpl.php


If that doesn't work, try:

page--announce-your-new-products.tpl.php


Unfortunately the docs aren't very clear on which way will work.