Hi .... We've left this up to the uploader, in that if he or she wants to offer a video tutorial as a download they can do as this user did:

http://www.sharecg.com/v/1271/tutorial/Creating-a-reflective-metallic-surface

In this case the uploader gave a short description and picture of the tutorial and provided a link to the .mov file in the description.

It's really up to each individual whether or not they want to allow others to download their material.

We do not have plans to make this a built-in functionality in the near future since we're working on some very big, higher priority, engineering tasks now.  We will revisit requests like this one once we've finished the Jobs and the Extended Portfolio funtionalities we're working on this month.