Like those who once worked in and around the trading pits, the physical trading floors had to be reinvented for a different role once trading became electronic. The most recent recent exchange to shut floor trading and go 100% was the Minneapolis Grain Exchange and their trading floor is now used as a collaborative office where people can rent desks for various durations and contractual commitment. The trend for "coworking" is pretty widespread across the US now and it's a great use of space at the MGEX because it is simply installing desks and chairs for the most part.
Thanks to Nathan Rudd of Minneapolis for the link.