Frontend upload for images, mp3s and video? I would like to allow users of our site to be able to upload images, mp3's and video from the front-end. Can I do this with the entry form template easily enough?

I was thinking maybe I could use Wistia for the video upload with their widget.
Yes you can do that with an Entry Form in your template.

Have a look at the assets fields article in the docs, there is a small section about uploading files from front-end forms.