Google adwords is not testing ads with the full domain name on the adcopy. It was first reported by www.seroundtable.com yesterday for search results in Canada but now it seems that Google is also testing this in the UK:
So far we noticed that only the first three results get their domain name to appear next to the Headline. In some cases though the domain name only appears on the second or third listing. We presume this depends on the length of the Headline and/or the first description line.