They're holding until the iron is hottest, up to a decade. The HQ2 cavalcade has focused and highlighted three parts of downtown - Reunion-Convention Center, Victory Park-West End, Smart Dallas (City Hall-Convention Center) - and these three will rule the massive scale development. Spire could sell or partner with Hall or Billingsley to thoroughly torque this downtown acreage into a Rockefeller Plaza sort of dealio.
I would absolutely love to see The Crow Asian Collection (or the Crow rare books, statuary and art collection) expand in dramatic form that aims the Arts District toward the Latino Cultural Center and that would include a Spire-Billingsley deal. But also, Hall is famous for Texas art collecting and the same effect could happen. Dallas could really use a prominent Modern Art Museum, though, and neither Crow/Billingsley nor Hall seem to have as much a taste for modern art.
Kicking off a new philanthropic collaboration founded by the Crow Family & Craig Hall would certainly demand the attention of Spire, could even command cooperation for a new venue in an Arts District annex.
Nothing much should be expected with the Spire property until the next lifetime of I-345 has been determined.