Something that would be useful, I think, would be for VM to get the speedtest app from
http://www.dslreports.com/speedtest but the Java version, and run it locally.
They could easily firewall it off so that only VM customers may use it, and it would present results to the DSLR servers in an easy to read and historical format, along with area information so that people could see where these tests are coming from.
The problem when an ISP is testing its' own service and presenting results to the public is, my humble opinion, it's too easy to be cynical about it. Using a 'neutral' speed testing application with publically readable results removes some of this doubt from people's minds.