From JS Online:
"In its various incarnations, it has been likened to a drill bit, a swirling ball gown, a soft-serve ice cream cone, a licorice Twizzler and a birthday candle. Whatever metaphor you choose, Santiago Calatrava's proposed Chicago Spire is a twisting, shimmering symbol of both the Windy City's downtown renaissance and its global aspirations.
"At 2,000 feet, the 150-story skyscraper would be the nation's tallest building, eclipsing Chicago's own 1,450-foot Sears Tower and muscling into the ranks of the world's most stratospheric towers in advance of the 2016 Olympics, which Chicago hopes to host."
Click this link for the rest of the JS Online story.
It's pretty cool, but I think Chicago is just jealous that Milwaukee has a Calatrava and it doesn't. Nothing like a little sibling rivalry.