I just seen the latest trailer for Mass Effect 3
See it here I recommend watching it in HD and full screen.
When I was watching it I noticed that in Shepard's squad was Garrus and James, and at the bottom of the screen, where their icons are, @ 0:42 I noticed that James' power was Singularity. Possibly suggesting he will be a Vanguard type class in Mass Effect 3.
Have a look and see what you think.