The first thing I did when I started my new Imperial Knight kit was break out a jewelers' saw and cut the left leg in half below the knee...
I wanted my model climbing through the rubble of a ruined building, but the same build could be used to make a knight charging across open terrain (3rd pic). The only fiddly bit of modeling was replacing the hose on the left leg.
I will have a step by step tutorial on my blog in a few days, but I just wanted to post these pics for those thinking about doing similar things. The rest of the construction should be by the numbers and boring.
I hesitate to rush the assembly of the arms until we see what kind of goodies FW comes out with. It would be awesome if they produce complete arm kits because you won't need magnets to swap them out, but I am afraid they might only make lower arm additions that would require you to use the shoulder joints in the main kit. I haven't decided on a house or faction yet anyway so I'm not in a hurry...