I've come across some news that will perk your day, I know what they were filming yesterday and the day before in NZ.

The scenes that were shot took place at the Rangipo Desert, at Tongariro National Park.

They were filming the Black Gates of Mordor scenes. All very intense and foreboading, I saw Aragorn stirring his army against tonns of Orcs.

I saw alot of cast members there, including:

Dominic Monaghan (Merry)
Billy Boyd (Pippin)
Ian McKellen (Gandalf)
Viggo Mortensen (Aragorn)
Orlando Bloom (Legolas)
Karl Urban (Eomer)

I also saw many body doubles for most if not all the main characters. There were also extras, about 150 of them, some dressed as Rohan Soliders, some as Gondorian Soldiers. There were also many many Orcs there.