if you used a shift lens on a 12-16mp camera (like the 90mm i have for my canon) you could in theory get a near 30mpixel image but you would get problems stitching because of people moving and the time it takes to shift.
CS3 has a really good auto stitching feature so if you quickly shot a left/center/right frame it would join seamlessly and deal with any parallax errors (as long as people didn't move too much)
"http://www1.istockphoto.com/file_thumbview_approve/3615573/2/istockphoto_3615573_transparency_film_frames.jpg"
if you used a shift lens on a 12-16mp camera (like the 90mm i have for my canon) you could in theory get a near 30mpixel image but you would get problems stitching because of people moving and the time it takes to shift.
CS3 has a really good auto stitching feature so if you quickly shot a left/center/right frame it would join seamlessly and deal with any parallax errors (as long as people didn't move too much)