the Dreadclaw is not an Assault unit, Imperial Armour lists it as deploying as per the drop pod rules, ergo no assaulting from it.

However, it is also listed as a flyer, therefore, unlike normal drop pods it is not immobile once it hits the table.

So, it works like this, dreadclaw comes in from reserve and deep strikes as per normal drop pod rules. it does not deploy a unit as yet. on the next turn, it lifts off moves a distance and sets down, deploys the unit inside who may then assault as normal, BUT that makes no sense because rules for flyers state that they must move a minimum of 36 inches in the movement phase, and rules for disembarking state that no model may embark or disembark from any vehicle that has moved flat out, 24 inches or more in one turn.