I know Krys is working on a flat chest morph. Also, on StudioMaya's site, there's a flatter chest morph. If you spin it above 1, it's decent for a male chest, though I'd post work it a bit at some angles.

Here's the morph applied at 1.7 with the chest itself xScaled to 110% with my Jaw2 morph on the face. I think it looks decent for a male anime figure, especially since my guys usually wear clothes. (Even the women do!) ;-)