As of 1.8.1-pre1, scoreboard records were upgraded to remove a matching UUID record for scoreboard objectives of an entity that is deleted. For example, after tossing an item on the ground:

/scoreboard objectives add OBJECTIVE dummy
/scoreboard players set @e[type=Item,c=1] OBJECTIVE 1
/scoreboard players list

The UUID of the item will be seen on the list as expected. Pick up the item and the record will be removed (you can check by using the 'list' function again). However, if an entity is inserted into a team (using a creeper in this example):

/scoreboard teams add TEAM
/scoreboard teams join TEAM @e[type=Creeper,c=1]
/scoreboard teams list TEAM

And then the entity is deleted, the record in TEAM will remain. Unsure if intended, though I felt it should be mentioned considering the change to objectives.