1.  There would be no electronic devices.

2.  No video Games nor Movies.

3.  No cars, busses, trucks, or any other motorized vehicle.

4.  There would be no weapon other than Medieval technology... possibly not even that.

5.  No one would ever land on the moon.

6.  Neither Communism or Capitalism would exist, only dictatorships, monarchies, or anarchy.

7.  Mathematics would be a dreaded subject, if it was even comprehended.

8.  Everyone would be an author of at least several fantasy books.

9.  There would be to many fantasy books for man-kinds good.

10.  Only people with the right moods at certain times would like mystery fiction.

11.  Everyone likes history.

12.  No body likes horror novels.

13.  Paintings and other pictures would be of the poorest quality, though the people would like to draw.

14.  There would only be a 25% chance that humans would advance beyond Medieval or Dark Age technology.

15.  Cats would, most likely, be extinct.

16.  Everyone would dream of being a good artist.

17.  Everyone would think that their brothers (even though they are the same as him/her) were very odd.

18.  Only a certain measure of politics would surface in the busy, and befuddle minds of the nobles.

19.  Everyone would hate swimming pools or anything water related (i.e. showers).

20.  Hiawian Punch would never have been invented.

21.  Henry Ford would have spent his time dreaming up things he called a "Model T", not actually making it.

22.  Pink would be outlawed.

24.  Buildings would be sloppily constructed.

25.  The likelihood of bread being discovered by growing wheat and grinding it would be very, VERY, slim.

26.  Everyone would be saying "Politics equals, disguised lies."

27.  Leonardo DVinci would have finished most of what he started, unfortunately, that would only be a series of fantasy books.

28.  Kids as old as 12 would have an interest in politics.

29.  Kids 12 and older would be attempting to take over the world...

30.  Hand pumps would have never come into the mind of it creator.

31.  Everyone would hate Legos (though... I must say myself that that wouldn't be such a bad thing...)

32.  It would have taken a genius of his era to invent the bow and arrow.

33.  A genius 33 times that would be required to invent ballistas or catapults.

34.  If boats were built, no one would be able to comprehend how they floated, let alone sailed against the wind.

35.  Markus Perrson, the creator of Minecraft, would have written a fantasy book called, Minecraft, rather than making a video game.

36.  Everyone would eat butterbread for lunch, breakfast, and super.

37.  Macaroni and Cheese would be one of the top three favorite foods of every one, along with Pizza and Chicken Cordon Bleu.  (I don't see a consequence here though...)

38.  When someone said "genetically reverse engineered it" the other person would run away screaming.

39.  Everyone would be inventing a slew of new words weekly.

40.  The bill that says "The right to bear arms" would be abolished for its silly wording.

More to come probably, those are just the ones I thought up real quick.  :)