Adopt Adam Barth's proposal as a source of cryptographically strong random numbers, but with an API based on binary_data, and made available (somehow) via the module system rather than introducing yet another property on the global object. This comment explains one of the problems with simply adding this to the global object.
Harmony random-er proposal.
David Wagner's links on randomness
Wikipedia’s Cryptographically secure pseudorandom number generator
Adam Barth's proposal which this strawman now proposes to adopt. implementation progress.
Mozilla's alternate unimplemented API and implementation progress.