I was screwing around on my rogue, and found an interesting exploit as I died by a mob of mobs. While running away, I hit sprint (with around 200 health remaining), and died shortly thereafter. While running back to my body as a ghost, I found that I was running faster than usual, even faster than my NE in spirit form (rogue is a human if that may make a difference). I do not know if this will also work for a druid's dash, as you shapeshift out when you die...
Unfortunately, it does not show as a buff while dead, it's something that you have to deduce visually as you run. Sadly, this also means that screenshots are useless. Sorry, those of you that need a screenshot before giving it a shot.
EDIT: Appears that others are unable to reproduce this, my apologies.