The video on the Road Test main page is fairly descriptive. Essentially Element14 places items up for themselves and others (like Agilent, Tektronix, etc...) and users create proposals. If your proposal gets selected you are required to at least produce a well thought out review for the product which they provided. In some instances blog posts about the unit are required as well.
Edit: Almost forgot, in exchange for the review you get to keep the unit.
