As of May 16th, 2019 BrightTALK Webinars can easily be tracked in Pardot using the "Activity Message" field.
This field should be created in your Pardot instance as a "Text" field, with the option "Record and Display Multiple Responses" checked and then mapped in your BrightTALK Demand Central Account:
This field passes the following values:
-Registered for [Name of your Webinar]
-Viewed [Name of your Webinar] Live
-Viewed [Name of your Webinar] On-Demand
You can then report on BrightTALK webinars at any time using a Dynamic List. Below is an example Dynamic List of all leads who registered for "Kubernetes in the Cloud":