Also remember that they are working on static RAM to replace the HDD. Soon we won't even need harddrives because the static RAM can hold the information. This will be much more secure. Anything spinning at 7200 RPMs is going to fail sooner or later. RAM is less likely to corrupt. So probably the more RAM support the better.
Samsung are the main entity working to replace HDD's with Flash ROM
(yes, Flash memory is technically ROM, this is due to it being based on EEPROM, whose predecessors include UV EPROM and PROM).
It is important to know the distinction between RAM and Flash ROM because one is volatile (RAM, when the power goes off you loose your data), and the other is non-volatile (the bits are static even without power).
There are RAM Disc solutions which allow you to have 4GB RAM Drives, these are suitable only for HEAP type database tables due to their volatile nature.
Flash ROM is the most suitable type of memory currently avaliable to replace HDDs. However, due to the design of Flash ROM it is likely it will always be slower than DRAM in terms of access speed. However it will still be faster than HDD due to it's solid state nature, giving it 'instant' seek times.
You guys are forgetting a few things about jumping the number of bits of a CPU, cost. A 32bit databus requires 32 wires, a 64bit requires 64 wires, however a 16bit only requires 16 wires, this made the transition from 16 bit to 32bit less costly than the transition from 32bit to 64bit.
I should also mention that EM64T from Intel means Extended Memory 64, which means that it can use a 64bit database to address 64bit memory addresses for greater than 4GiB of system RAM. Single clock 64bit integer operations have been avaliable in Intel processors since MMX. Heck, even now they can do 128bit single clock integer operations with the SSE instruction sets.
Of course the issues are _alot_ more complicated than I have presented here, and heaps heaps more complicated than you have presented in your arguments Newfie.
Obiviously we should keep watching new technologies because one day DRAM will be replaced with something even better, as will Flash ROM, and the CPU as we know it won't exist in the same manner as it does now.