While I agree that 64 bit is not yet mainstream, it has to happen. Windows will eventually have to go 64 bit only as 32 bit support only up to 4 GB of ram. The unconfirmed reports suggest that windows 9 will make that switch but don’t worry, it is not yet time. I cant read the future but I do know that the current windows 8.1 requires 2 GB and not 4 so I highly doubt that the next one will suddenly require above 4 considering how windows 8 runs faster than 7 while using less resources.
Once again I do not know the future nor work at Microsoft but logic and common sense suggest that we will still get a kick out of our 32 bit hardware for about 4 years. Awaiting the official confirmation from Microsoft soon.