That's exactly what I was talking about in the other posts about sitting all day, etc. Hydraulic desks aren't new, they've been around for years. They're popular in call centers that operate 24 hours a day so different shifts can set their desks up the way they like them. The good ones have memory so you can recall your favorite settings at the touch of a button.
Herman Miller, Steel Case, and Teknion (who my girlfriend used to do sales for) all make them. Even Ikea's office furniture line up has the bases to accept any of their universal desktops.