The following is not intended to be a bash of the standing desk, which I see as a reasonable thing to consider. Rather this is to put some experience behind my skepticism of all of the "shiny, new health enhancer" methods of modern advertising.
If anyone remembers back in the early 1970s (those who were alive back then), the new health "must-do" craze was the Earth Shoe. It seems some Scandinavian "researchers" (why are they always Scandinavian?) observed footprints in wet sand and found the depth of the heel imprint was greater than that for the rest of the foot. (Editorial comment: DUH! That's where most of the weight of the body is transfered to the ground). Anyway, they suggested that the lower heel position was the natural position, and thus the best position for footwear, so they designed the Earth Shoe to have the heel significantly lower than the rest of the foot. I sucked all of that up because the Earth Shoe became the newest cool thing for all of the wanna-be hippies (those who liked the hippie look but didn't want to dive fully into the lifestyle). So I had my pair, along with jobs that kept me on my feet for most of the working day and into the working night (I was in grad school and working three jobs). To shorten this rant, I can trace my three-plus decades of lower back problems to the very time I donned those fu**ing Earth Shoes. Their run in the cool new health fad spotlight didn't last long, and I suspect they disappeared due to more than just a fashion shift.
Again, I'm not drawing a parallel to the stand-up desk. I'm just saying we all should be skeptical enough to do our homework instead of falling for any health-related miracle claims from marketers, particularly those who state the life-shortening risks of avoiding their product.
NOTE added in edit: I second the lutefisk comment, although I do love my lefse.