3. Legolas' Dad
The beauty of having all the films made in one go (minus the extensive reshoot to extend the series to a trilogy), is that characters who dont become key until later instalments can still play a small part early on in necessary. One great example is Thranduil, the wood elf king who stands idly by as Smaug attacks Erebor. As well as making his later appearance (he certainly isn't Thorins biggest fan) mean more, its particularly cool as he happens to be Legolas father. Also worth noting (but more well known) is that Gloin (one of the more sidelined dwarves) is Gimlis Dad. Given the conflict between races I doubt these two will be playfully killing together. Expect to see more of Thranduil come The Desolation of Smaug, as well as the return of everyones favourite archer.