The particulars of the proposals that at least five development teams will file today with New York's Metropolitan Transportation Authority are sure to differ somewhat in their respective visions of the future of Manhattan's gritty Hudson Yards district. But the plans will certainly all be powered by the same overriding conceptual engine: this contested site is -- no pressure, folks -- intended to set Manhattan on course for the 21st century and save the city from global obsolescence.Large and raw, Hudson Yards isn't just another development parcel. It's a very real and potent extension of what is already the nation's largest, wealthiest and most powerful Central Business District. It's a new piece of -- not just a new adjacency to -- a market that is the very definition of high barrier to entry. But even before a piling has been driven into what will likely be the billion-dollar decking over of the rail cut that is Hudson Yards itself, the site bears the expectations of many constituencies: City Hall and Albany, the would-be developers, the larger real estate industry and the city's business interests, and of the local and regional community.