With the HTML5 trial you can watch YouTube videos from DEVONagent and DEVONthink even without Flash installed. Forum user Greg Jones:
“I did not install Flash on my 2011 MacBook Pro and for the most part I have not missed much without it. For YouTube videos I have been using a Safari extension that supports HTML5 videos, but that didn’t help me with the DEVONtech products. I just discovered today that there is a HTML5 trial available for viewing YouTube videos. SIgn-in with your YouTube account, opt-in the trial, and you can watch YouTube videos from DEVONagent and DEVONthink.”
Cool tip, thank you!