I work in an IT dept which supports almost a dozen departments that all told use about 30 or 40 apps, almost all of which are still 32-bit. The hardware is recent and all 64-bit (as is our OS) but even the MS Office we use is 32-bit because of interaction with other apps. We also have to default the browser to the 32-bit IE executable rather than the 64-bit because of plugins (even MS recommends this). Most vendors still aren't up to 64-bit yet because they don't want to shut out the customers that are still years behind on upgrading. I'm thinking 32-bit will still be around for another 10 years to be on the safe side.
When I worked at a university, we had several pieces of legacy 32-bit software, mostly written in C, which were essential to some courses. It became more and more difficult to run them as Linux distributions stopped shipping 32-bit libraries by default (I think Scientific Linux 7.1 caused a lot of problems because of this).
