I rather suspect that the opposite is true.
If you Google around have been several benchmark comparisons, generally 32-bit software run on a 64-bit OS system is at best marginally faster, but sometimes marginally slower... Essentially it's a wash for most 32-bit software...
I wonder how long it will be before Intel et al. see a dip in their revenue stream and release the increasingly pointless 128bit blunderbus.
I see nothing pointless about it, progress happens and although I love 8-bit CPU arcade games and enjoy 8-bit micros, I sure as heck would not want to be stuck using only 8-bit hardware exclusively in today's computing world...
It's hard to predict the computing future and I think the 64-bit will be mainstream for quite some time as the software and even hardware is far from exploiting its theoretical limits, that said 32-bit computers had their day, but the reality is they are no longer able to keep up with the demands of many in today's computing world... I'm running 16GB of RAM on this laptop and wish I could cram more in as I can easily bog down the system and tax the RAM with just my daily multitasking if I don't pay attention, I can't even begin to imagine trying to run it with only 4GB...