lamRight said: "There are other types of movement blurs as well. This is just one venue. There is opacity movement, background movement, warped movement and combinations of the others. Each one has a different purpose and this is just one of the many used."
Let me guess:
-opacity to show the steps on how s/he got to that point
-background to show comparison to how fast the character is moving than with the rest of the area.
-warped, used that myself to show more curvature, like in my own comic, being sucked in in a spiraly way
-combination: maybe like bg / movement blur to make it look like its even faster?
Nice guide btw, though I could disagree on how to get those results because it looks like you used too much movement blur on some of your stuff which makes it look like they are tripping / removing their clothes at mach speed.