The "blobs" will show up best on a white background. The image below is one which i've "gamma"-down so that the spots are more obvious, to help you look in the right region of the screen.
NC10 users in the UK have brought them back to the retail stores they bought from to swap for new units. One person even checked 3 new sets with the same problem before walking out of the store with one without. This is clearly a manufacturing problem, and you should contact your local Samsung dealer to get it fixed.
As for me, since Singapore doesn't have Samsung coverage, I'll just have to make do, and avoid using white background. As of now, I'm blind to it.
Check out these sites:
http://www.google.com/search?q=nc10+blotches
