You know what Manhattan needs? More commercial office space! Thankfully, Mayor Bloomberg and some big shot developers are committed to building a 51 story tower on West 30th Street, creating 1.7 million square feet of new commercial office space. Today they announced that they've already locked in the first tenant: Coach, Inc., which will occupy the lower third of the building. It'll be so tall you'll be able to see it from your office in Jersey City! Here's what's happening:

Designed by Kohn Pedersen Fox Associates, the LEED Gold building will be prominently located on the corner of 30th Street and 10th Avenue, bridging the Chelsea and Hudson Yards. Coach will occupy the lower one-third of the building where they will create a vertical campus with a vast atrium serving as the visual anchor for the High Line. This central atrium will also be the heart of Coach’s space, and is reflective of the company’s collective and community-focused environment. The Coach tower is the south tower of a planned 5.5 million square foot “superblock building complex.

What, no monorail? At a press conference today, Bloomberg predicted that the completion of the #7 subway line and the construction of this first tower will "have a domino effect on the rest of the development" of the entire Hudson Yards area, a 60-block and 300-acre neighborhood. Construction on the giant tower is set to commence in mid-2012, to be ready for occupancy in 2015. When complete, it will be the largest commercial building in New York City. Eat your heart out, 1 World Trade Center!

The news comes on the heels of the announcement that Barry Diller, chairman of IAC and Expedia, and his wife, the designer Diane von Furstenberg, would donate $20 million to finish The High Line park. Once complete, the widest part of the park would extend right through the Hudson Yards development, to 34th Street. Here's more on the overall project, which has been in the planning/pipe dream stages for years:

The master plan for the Railyards comprises approximately 5,000 residences in nine residential buildings, 6 million square feet of state-of-the-art commercial office space, a 1 million square foot of destination retail complex, a 150-room five star hotel, a totally unique cultural facility, and a new 750-seat public school, all carefully planned around 14 acres of public open space. Key transportation investments are underway throughout the area around Hudson Yards including the extension of the No. 7 subway line. The No. 7 subway - on schedule for a December 2013 opening - will link the site to every major line in New York City, including the major subway nodes of Times Square, Bryant Park, and Grand Central Terminal, delivering exceptional access to Hudson Yards.

Through the construction of a billion dollar platform over the yards, the site will be transformed into a mixed-use neighborhood without compare. Hudson Yards will provide residents, workers and visitors with a destination that combines world-class private development with unique public parks and cultural attractions. Nearby attractions include the High Line, the extensive running and bike paths in the 5-mile Hudson River Park and the new Hudson Park and Boulevard, a sweeping 4-acre thoroughfare from 33rd to 42nd Street, creating a network of parks and public plazas that weave throughout the West Side.