Shimano cassette compatibility I am upgrading my mtb, an '04 Specialized Epic. Currently, it has a Shimano 9sp cassette on Mavic xm317 wheels, and I am looking to change to a 10 or 11 speed cassette. I am aware that I need to change shifters, derailleurs etc to get this to work, they are not part of the question.

My question is: With all Shimano components, is the limiting factor in compatibility the hub? Are there other aspects/parts which limit compatibility with newer cassettes?
Mountain hubs are the same for 8, 9, 10 and 11 speeds. 11 speed cassette is wider, but instead of making the freehub body wider, the largest cog hangs slightly over the freehub body. This means that it is possible but not likely that there is clearance for derailleur with 9 or 10 speeds but not 11.