OK folks, calm down. It's true that I am interested to know what screens the M1710 comes with in all areas of the world. But wadham is also totally correct in saying that the reason I started this thread was to verify that Dell had replaced my screen with the wrong type of panel, and to obtain the information I needed to challenge Dell on the matter.
My Dell tech support contact has escalated the issue to his supervisor, who was supposed to call me back today. Unfortunately that didn't happen, but the tech support guy (who is an absolute star, by the way) called me to apologise for his supervisor being too busy to call me today, and to assure me that I would definitely get a call on Monday.
Interesting that xeronex has a M1710 with a Sharp panel (as stated
here), apparently disproving the theory that only the Samsung screen is used in UK versions of the M1710.