Here is Lesson eights updated content for the StarTrooper 2D XNA tutorial now for GS4.0
The blog tutorial is over on http://xna-uk.net/blogs/darkgenesis/default.aspx, so visit there for more info and to follow the tutorial.
The project has now been update to the RTM of GS4.0 plus the windows and windows phone projects have now been combined.
This now has a single project for both platforms. You can also copy the windows project as an XBOX project if you wish (although this hasn't been tested)