Templates creation now allows adding attachments and tracked presentations. Just select "Insert Attachment" from the bottom of the Templates editor and select the file of your choice.
PDF and PPT files will prompt the tracked presentations window, giving you the option to allow recipient downloads and require a name to view. Once your template has been saved, you can also add those Templates to Campaigns, meaning that your Campaigns emails can now include attachments:
When tracking from Campaigns, be sure to check off "Track Links & Template Attachments" in the settings to the bottom of the window in order to collect attachment tracking events.