Vint Cerf himself cowrote a post on the Official Google Blog to explain the move.  Along with Stephen Stuart, he called Measurement Lab (or M-Lab) "an open platform that researchers can use to deploy Internet measurement tools."  And more specifically, the tools will "measure the speed of their connection, run diagnostics, and attempt to discern if their ISP is blocking or throttling particular applications."

Google’s participation should get M-Lab (which is, of course, in beta) off to a fast start as it’s providing researchers with 36 servers in 12 different spots across America and Europe.  From there, other companies and individuals may glob on, helping to create a solid picture of the worldwide state of broadband communications.

Then here’s the payoff: all of this info will probably wind up being used in an argument for net neutrality.  Also, it wouldn’t be surprising to see several accusations of false advertising (in regards to download and upload speeds) brought against ISPs along the way.

As for how those ISPs might now feel about Google, it’s almost hard not to wonder whether it’s a coincidence that offline access for Gmail was introduced just hours before M-Lab.