"Mark, just go in to "P" mode and you'll have access to WB presets as well MWB. You may have missed that. In fact you can even adjust the degree of WB shift using a grid."
Ken, unfortunately, I think you may be wrong on this one. While it is true in 'P' mode you have WB choices, 'P' mode is a still mode. If you press the movie button in 'P' mode, the camera goes into iAuto mode (see the icon on the screen).
Now the question is, did the camera retain the WB setting from 'P' mode when it went into auto mode? I do not think so, although it might have started at the WB setting, it may then change it according to auto mode protocol.
Similarly, if you set the camera to 'M' mode, you can set shutter and iris and iso. But I do not think that if you press the movie button when in still 'M' mode it keeps those settings - again, after pressing the movie button the camera goes into 'iAuto' mode no matter what still mode you are in.
Do you have experience that suggests otherwise? There are essentially no manual controls when shooting video, except spot focus selection and ev compensation (both of which I use a lot).
I wish what you claim were true.