Over in the Union Station neighborhood, East-West partners is proposing an 18-story, 320,000 square foot office development. This would seat right next to the millennium bridge. One unique aspect is the helical parking structure (which is a little contradicting given this is going in Denver's largest TOD-area)
Here are some conceptual renderings from DenverInfill.
http://denverinfill.com/blog/2012/04...-chestnut.html
http://denverinfill.com/blog/2012/04...-chestnut.html
And a picture of the site:
http://denverinfill.com/blog/2012/04...-chestnut.html