Another perk to using the Stormraven as a delivery system is that if the Stormraven gets destroyed, your units are already where they need to be, unless the opponent has blown it up right away (which shouldnt happen if you put the Stormraven in reserve, thus protecting it from that first wave of fire). As long as your units can survive the possible explosion (Terminators have a very good chance of surviving, along with a dreadnought), then they are right at the enemy line waiting to attack. The Stormraven still accomplishes a portion of its mission even if destroyed early. The next advantage comes from the units embarked inside, just waiting to get out. If the player embarks an independant character, a unit of infantry, and a dreadnought inside the Raven, then all three units can be separated while disembarking, and can charge three separate units! Not bad for one vehicle creating so much mayhem.
A favorite tactic of mine involves tying up a key unit or troop with the dreadnought, knowing that the strength of the attacking unit is not strong enough to even hurt it. It also keeps the dreadnought from getting shot at, since it is locked in combat. If the Stormraven is still flying around after delivery of the units, it can shoot at a unit of interest such as a vehicle (if it has the twin linked multi-melta or lascannon on it), and if the shooting fails, the dreadnought can fire and charge the given vehicle. Dont forget that certain armies, such as the Grey Knights, have fortitude on all their vehicles and walkers, giving them the ability to completley ignore shaken AND stunned results. This extra bit of survivability can help get that Stormraven or dreadnought that much closer to its objective. The dreadnoughts also have Reinforced Aegis, giving that unit, and ANY unit within 12" of it some added protection from psykers. The Reinforced Aegis makes psykers take their leadership tests at a -4 to their leadership value, so a leadership 10 psyker now needs to roll a 6 or under to get his psychic power to effect the dreadnought or any unit within 12" of it. This added bonus is specifically advantageous when the dreadnought is kept within 12" of the other unit that was embarked within the Stormraven, giving extra protection, firepower, and assault capabilities to the units inside.
The amount of firepower and troop support that can come from one Stormraven is quite substantial, and while it can become a costly combination, the tactical flexibility and speed by which the Stormraven gives the other units, can change the overall play speed and layout of the battle. While there are still a lot of risks involved with such aggresive tactics, I believe that the positive impacts of its use outweigh the potential risks. Is this tactic going to win every game? NO. But is it going to make your games even more fun and exciting? YES!