Yes! The XNA Games Studio 3.0 CTP is available and it enables game development for the Zune platform. Canadian colleague Jean-Luc David ported this game pretty easily.
Jean-Luc's learning's in doing are:
· Project needed to be converted from XNA 1.0 to 2.0 (using the Migration tool)
· Copied in PreferredBuffer attributes from the Alien Takeover game, Mitch Walker’s reference game was very useful in general
· All graphics were reduced by 40%
· Background same aspect ratio - 90 degree clockwise rotation
· Removed all keyboard related code (everything in the #if!XBOX blocks)
· Used keyboard conditional statements for input, but targeted GamePad (eg: gamePadState.DPad.Left == ButtonState.Pressed)
· Fire == Buttons.A
· Rotated text in DrawString using MathHelper.PiOver2
· Added more ships, game appears to run faster on the Zune than on Windows
· Needed to adjust math in the game to rotate game (forced me to brush up on Cartesian math) :)
An interesting development I shall enjoy exploring.