Microsoft will give away free development tools to students world-wide under the Microsoft DreamSpark student program.

Microsoft DreamSpark is available to all students whose studies touch on technology, design, math, science and engineering.
The free Microsoft developer tools for students include Visual Studio 2005 Professional Edition, Visual Studio 2008 Professional Edition, XNA Game Studio 2.0, Expression Studio, including Expression Web, Expression Blend, Expression Design and Expression Media.
Additionally the SQL Server 2005 Developer Edition and Windows Server, Standard Edition are part of the free software program.

Developer support has always been a key component of the Microsoft OS dominance. With Linux growing up more and more it is necessary to get the next generation of programmers on their side if they can.
More details on the MSDN Site.