I fired up my Curse Client this afternoon, and lo and behold, there's an update available for GridStatusRaidIcons!!
Yes, this is that Grid module a bunch of us were trying to uncover from the locked bowels of the wowace forums a couple months back! For those out of the loop, this is a Grid module that will add the graphical raid target icons as a watchable status option. Personally, I set them up with the GridCornerIndicatorIcons module (separate download) so that one corner shows the person's own mark, and a different corner shows the icon of their current target (if any).
GridStatusRaidIcons is available from the Curse website here.