[curiousuburb]

For things like military-grade cryptography, or perhaps environmental modeling of weather on planetary scales, or cosmological and astronomical simulations of the entire galaxy, 64 bits would help.

For most 'regular human' tasks, it isn't as significant as it sounds, or as necessary (yet). The number of tasks that require 64-bit computing is still relatively small, or have up until now been kludged with lesser power applied more inventively.

Even protein modeling (Folding@Home) can be handled by distributed clustering of millions of humble 32-bit 'joe average' home computers. Not to say somebody might not write a 64 bit version to test more complex structures...

The only real 'speed' benefit is that 64 bit systems can do extremely large numbers in one chunk... 32-bit systems may require two computations to simulate the same values...