I'm sure MSG will sue the city. They've said that they meet the qualifications for a permit extension, but the city just doesn't want them there anymore. I'm not a lawyer, but I believe MSG owns the land as well as the rights above it so I'm not sure they city is totally within their rights to tell MSG that they have to move their building. If they want to take over the property, I think they have to use eminent domain, which is different from limiting the term of their land-use permit. Eminent domain would entitle MSG to "fair market value" for their property, which I would imagine would be several billion dollars when you take into account all the money they just spent on the renovations plus the value of 2 city blocks in the middle of midtown.
The Madison Square Garden Corporation purchased the air-rights to Penn Station from the Pennsylvania Railroad back in the late 50's. It took them 6 years to draw up plans, get the necessary approvals, and finally get the jack-hammers moving. The building is private property. Amtrak owns what is left of Penn Station, and that is all underground.
If the City is really going to attempt to evict MSG, they'd have to pay fair market value for the property. That will be litigated for years. Then, they will have to demolish MSG and the office tower on the 7th avenue end of the block, in order to prep the site for a new head-house. That will cost even MORE money. Then they need to design and construct a new head house, and that is just more money. It is not money well spent. NONE OF THIS WILL IMPROVE THE CAPACITY OF PENN STATION. The Station needs more tracks, and more platforms. The only way that is accomplished is by expanding Penn Station south to 30th St, and north to 34th Street, and building new tunnels under the Hudson River. And that my friends is VERY VERY expensive. And with the new tunnel to Macy's basement scuttled last year, the cost will just keep rising. If they couldn't afford it last year, I don't think they can afford it this year or ten years from now.
If the goal is to increase Penn's capacity, build the tunnels and tracks and platforms first, then worry about the ornamental head house. The heart of the station is in the trackage.
The City's actions are just postering, to demonstrate to the public that they are pro-transit. A city that is crying poverty has no business undertaking this action.
In ten years the Garden will get another ten years. There simply is no money for this improvement.
Cheers!
-Doug