The Good News: The new Sparrows are available on Amazon.
The Bad News: All the Mega Construx Destiny sets at my local Target are on clearance except for the Sparrows and the Armories (the latter of which being odd because the Armory sets are all Wave 1). This is bad because it includes the Hive Horde Attack set, which is the newest set they had in stock. This suggests they might not carry any more sets from the Mega Construx Destiny line.