Dell is taking a hit and the culprit is likely a greater demand for low-end PCs from non-commercial buyers. Of course, the economic downturn is a player, but even more so, could it be that a fundamental change is taking place in the minds of PC buyers?
Coming full circle, the PC is about getting basic things done. Really, the high end bells and whistles come up short more often than not for home users and the the advent and flood, or perhaps more importantly the idea of netbooks has effected a change in the way people think about personal computing. Dell's problem here may not be so much about the machines, but more about the machine users.
I'm going to go out on a limb here and write that most non-commercial users don't know how to leverage the power of a high end machine. Here, high end machines aren't realizing actual value. Microsoft's cumbersome operating systems play a part in this problem. Selling the machine to vendors before it's sold to the user is probably another one. Trying to generate revenues outside of core products typically presents a challenge.
PC users are making especially practical buying decisions and most have been there and done that. Welcome to the new, re-characterized PC.