"They're always after me Lucky Charms! They're Magically Delicious!"
The lineup has changed occasionally over the years
shooting stars was added in 1998 which makes it 11 so I couldn't add that.
Generally as General Mills introduces new shapes, older marshmallows are phased out. The first "marbits", as they are called, to be phased out were the yellow moons and blue diamonds, as General Mills introduced their "Pot of Gold" marshmallow. Since they already had a yellow marbit, they changed the yellow moons to blue moons and eliminated the blue diamonds.
Recent changes to the marshmallows include: the star shape took more of a "shooting star" design, the orange 5 pointed star being added together with a white "trail" (though making the 5th point in the star almost invisible.) More recently, in late 2005 another different kind of marshmallow was added, the "Hidden Key". It is a solid yellow marshmallow that resembles the shape of an older designed door (similar to the shape of a tombstone; flat at the bottom, flat sides with a round top). When liquid is added to the cereal, the sugar inside the marshmallow dissolves and the shape of an older key "appears" as if "by magic". The new tagline for this is "Unlock the door with milk!" This "new" marshmallow type has been used in other kinds of hot and cold cereals, but with mixed success. (from characters "hidden" inside a bigger marshmallow to letters appearing) Also to note, this new "Hidden Key" marshmallow only appears in the "regular" Lucky Charms; NOT in the Chocolate or Berry Versions. In early June, 2006, General Mills introduced a new Lucky Charms marshmallow, Magic Mirror marshmallows.