You know, I really have to agree with both of you on this in ways. It's just at that point in the 32-bit/64-bit transitional market that you really make valid points that are true both ways.
As an example, I went to our Wal-Mart and looked at every computer they had on the shelves, desktop and laptop. Now, our Wal-Mart store is pretty small, but they still have just over a dozen different computers. And if someone in this town (a podunk little place in northwest Kansas mind you) wanted to just go pickup a computer off the shelf, this is where they are going to do it!
Looking over all of the computers there, only two computers did not have the hardware to support a 64-bit OS...and those were an ACER netbook with Intel Atom processor and an HP netbook with Intel Atom processor. EVERYTHING else in the store was at least 64-bit capable. Now, of the dozen computers there, only two had 4 GB of memory, while all the rest had 3 GB or less. This means that the major benefit of 64-bit computation is really void on these systems. However, in a few cases I noticed that these computers with less than 4 GB of memory still came with Vista Home Premium x64.
Now, from the perspective of marketing, most people coming to pick up one of these computers off the shelf don't have a real clue between 32-bit and 64-bit, so if you are slick in wording "Now with 64-bit OS for future upgrades!" then people will jump for that. Why? Future proofing and the idea that it will make their computer faster. When in reality, there won't be any performance benefit or speed increase when their system still only has 3 GB (the most common amount) of RAM.
Now, looking at some fundamental rules of economy, a business who adapts to and utilizes the newest technology will be able to lower their estimated total overall expenses and of course, attract customers who are looking to keep up with the incredible fast-pace of technology. This means that the company adapting the best technology will edge out companies that don't from the market. Companies like Dell, HP, Acer and all the rest know this. Even if it's beyond pointless to update their computer lines constantly with a slightly faster refresh of a processor, or add options for a slightly faster graphics card for a mainstream desktop, they know that by offering the latest and greatest, they show they are adapting the best technology and will edge out the competition for it. It is also what pushes the technology and market to grow.
For the majority of home users, even a dual-core processor is often overkill and as Techman said, left sitting idle most of the time. But as technology advanced, the dual-core processor became "hot stuff" and a marketing scheme all in itself. As technology increases, the dual-core processor became much more widely available. Even though the greater public didn't really need the benefits of dual-core processors, they became common place in desktops and laptops, advertisements in an of themselves for the likes of major companies. The same can be said about quad-core processors, video cards, and all other hardware advancements really.
Getting back then to the 64-bit operating systems, when you look at what it costs to OEMs like Dell in difference between installing Vista Home Premium 32-bit and Vista Home Premium 64-bit the difference is negligible. So while the system may only have 3 GB (or even less) of RAM and may never even see a 64-bit program ever run on it, why NOT install the 64-bit operating system? In general it is still going to run all of your 32-bit applications (and this is getting more efficient and stable every day) and it already has a marketing hype in itself pushing its sales. If the average Joe then runs into some kind of compatibility issue with some old printer or an old card game not working on their new computer, the average user is going to get rid of it and update. This is also where many of the big OEM stores make their next move to get the customer to upgrade to THEIR products to keep up to date, heh.
Now, with businesses the story is somewhat different of course. Compatibilities with other equipment and software is a much bigger deal. This is the reason why they have technology people to do research on that and know about the differences between 32-bit and 64-bit computing and bring us right back to our debate core again. But really facing the facts here, its is not the businesses that drive the marketing points or standardized hardware for computers today, but the average consumer.
