[goblin89]

I was of the similar opinion, but a research[0] suggests that sitting straight is not actually as healthy. I'd like to see a source which would confirm that sitting back causes distortion to spine shape.

That said, I agree with you that an ergonomic chair would make little sense for a standing desk, as one will obviously sit less (only when too tired to stand).

[0] http://news.bbc.co.uk/2/hi/6187080.stm (2006)

[hapless]

I don't think it's obvious at all. I prefer to sit, but I am by nature a restless individual. A standing desk would allow me to make some of my pacing time productive.

To put it another way: every person may have a different use pattern when given the option of equal comfort at seated and standing heights.