While this update does add two new parts and a new game mechanic, there doesn't seem to be much opportunity to use them to expand on the existing game play.
The LP1 is a reusable rocket which you can land after stage separation. A succesful launching allows you to launch it again at a reduced cost ($1,000,000 compared to the original $4,000,000). This reduces your budget for subsequent launches of LP1 by $3,000,000.
Unfortunately, the only time you can take advantage of the savings from the LP1 is in the very last mission. The LP1 doesn't provide any benefit in the sandbox mode (other than the fun of landing the rocket), since you have an unlimited budget in the sandbox. I would have liked to be able to replay the previous missions, such as ADS Phase 2, using the LP1. Perhaps adding a platinum status for those able to lower the mission cost even further using the LP1. Allowing the LP1 to be used on previous missions would have increased the play-ability of this update.
Large Comms Satellite
This is a new medium sized part. It has non-retractable solar panels which generate 30 power. The comms satellite consumes 6 power. It doesn't have any cargo space.
Unlike the smaller comms satellite, it does have thrusters. However, the reverse thruster is missing. It also has a docking port which allows it to be refueled and attached to other vehicles.
The large comms satellite has some interesting geometry with the docking port off center. and parallel to the large solar panels. The large solar panel and the orbital laboratory both have the solar panels extend perpendicular to the docking axis.
I would have liked to see this have retractable solar panels, and a slot for a battery. That would have been an interesting mechanic to allow for it to run on battery for deep space missions, but then also to deploy the solar panels to recharge when near the sun.