Bioware have released a version of the CG trailer for Mass Effect 3 starring female Shepard.
Matt Rhodes - Mass Effect and Dragon Age Concept Art
Matt Rhodes provides a look behind-the-scenes at some early Mass Effect and Dragon Age designs. (Fixed link)
Pixologic - Interview with Bioware about Mass Effect 3
Pixologic have an interview with several artists from Bioware about their amazing work on Mass Effect 3.
Brian Sum's Concept Art for Mass Effect 3
Check out this gallery of beautiful concept art that Brian Sum has created for Mass Effect 3. (Beware spoilers)