Tom's Restaurant (2880 Broadway) is key piece of popular culture history. Not only did it serve as the inspiration for Suzanne Vega's "Tom's Diner," its exterior was used as Monk's on Seinfeld. According to Gothamist, Jerry Seinfeld and Jason Alexander are at Tom's Restaurant now and Jason Alexander's attire evokes fond memories of George Costanza. This can only mean good things.
Gothamist reports that the restaurant was closed for a few hours and had its shades down, as there were cameras inside and cables running out of the building. They also snapped a photograph of an orange film gear container labeled "Comedians," which probably means this is all for Seinfeld's web series Comedians in Cars Getting Coffee.
Whatever they're in there filming, it's no doubt pivotal. This could be more history in the making.