CiviMail Slow in loading with a significant number of message templates

WIth the current way that the CiviMail calls for the basic properties, we are currently loading the full content of every message template into the DOM when CiviMail initially loads. This can cause problems when you have a significant (possibly somewhere like 50 - 60 or more templates haven't tested the point where it hits an issue)

This slows down the loading of the CiviMail interface. The better solution is to when the template gets selected as an option in CiviMail that it loads the html / plain text content and the subject line. So have on the initial load only load enough information to populate the drop down list. This is also evident by the comment in line 134 of CRM/Mailing/Info.php