Plus, things have been advancing on the client side as well. No one wants to buy the latest version of Windows if the only major feature is that Microsoft squashed a lot of bugs and fine tuned performance. If they tried pushing something like that, it would make the marketing disaster of Vista look like nothing. We all want hundreds of new features, even if we will probably never use 99.99999999999% of them a single time. Those features require resources, whether we are using them or not, so the hardware has to advance to keep up. Plus Intel and AMD are interested in getting you to continually buy new chips, otherwise they won't keep making money and will go out of business. So depending on how you want to look at it, it's either a vicious or virtuous cycle.