Being a superstar does not ensure that a player will stay with one team for a long time. There are a number of other factors at play, and this could lead teams to deal talented players for huge returns.
Some teams will look to deal their stars that are closing in on free agency so that they can get something in return for them. Other stars may be dealt because they do not mesh with the current roster that they are on.
Blockbuster deals are also interesting because they can have a significant impact on the league. There should be at least a few of these deals in 2013.