It basically mentioned the new Microsoft initiative where
This is fantastic news, as previously that "Load Test Virtual User Pack" cost around £4000 per license and only added 1000 users at a time (this is on top of the already expensive £12,000 odd Visual Studio Ultimate license!!)"active Visual Studio Ultimate with MSDN subscribers are provided a license key to generate UNLIMITED virtual users without having to purchase the Visual Studio Load Test Virtual User Pack 2010."
Note - all prices are approximate (read .. in my head)
More details can be found at the Microsoft article:
Visual Studio 2010 Load Test Feature Pack and Visual Studio Load Test Virtual User Pack 2010 Frequently Asked Questions (FAQ)