A friend of mine mentioned a good point, that having all the motion degrees on one device limits simultaneous functionality, like the ability to spin while pulling up or down, etc. I can't see this being used much more than for driving and flight sims, just as what happened when they added analog to the 4 main buttons on their ps2 controller.
http://www.smashbros.com/en/characte...ra3/index.html
they added some character pages in the smash bros site