I think the point that some folks are trying to make is that forcing consumers of the API to use 64-bit machines is stifling innovation.
Many Twitter apps start as pet projects hosted on a shared HostGator or other provider's server for nine bucks a month. That's how mine started way back. You don't have the option of editing php.ini or running on a 64-bit machine, unless you want to reduce your groceries per month and fork out more for a server. Dewald