One unfortunately stupid consequence of the Devils allowing Josefson to play for them in 10-11 is that now he and Henrique are UFA the same year (2017). Now depending on what sort of contracts they sign that may not be an issue (and depending on their career trajectories, etc.), but I imagine 2017 is when the 'pain' from this contract might begin to be felt. Before that, it's smooth sailing through calm seas.
If Josefson, Henrique and Larsson are good enough that Zajac's deal might make it difficult to sign all of them when they hit UFA status, then we're in very good shape for the next four years.