There is no W3D plugin for max6, but on the last community gathering, EA representatives promised to release some sort of SDK and modding tools.
From what I heard, a 3dsmax and maya plugin will be included. The question is then: when do they consider it the right time to release it?
Oh, I do recall Aircraftkiller once had the plan to commercialise a plugin for 75$ or so, but the protest was to such an extend that the whole commercialisation was cancelled....(most likely also due to copyright issues).
Maybe if you blink real nicely into Aircraft's eyes he will give it to you...
