Hey there,
I too would like to be able to 'retreat' from a mission, as you can in original XCOM. I was playing UFOAI and got blindsided by aliens due to poor planning on my part. When I got my remaining troops to the ship and aborted mission, I was dismayed to learn that that means they all die. Please, consider adding this to the to do list for the next version!
That said, you guys have a great game here! Other than resolution change issues, which I would imagine have something to do with user privileges on Win7 and Vista boxes, I have had no issues. Once I visited the forums to figure out the resolution problems, I was on my way. Having loads of fun with the game.
-Adam