I am currently chatting with a good friend who is a Rohan Warrior extra…. when asked about costumes :

“oh we are just in standard sort of viking type gear – (person’s name) is playing as an elf and their costumes are kewl – he is one of the few guys skinny enough to fit them lol”

Filming at “Helms Deep” will apparently take 5 weeks…..so about 1 down and in the middle of week 2 I guess