I hate to sound smug (great South Park episode btw), but its really amazing to me how much even somewhat “saavy” computer users know so little about virtualization (and by saavy, I mean confident enough to post in some public forum about it.) There are so many misconceptions.. like:

• It’s just for software testers. While that was true at some point many years ago, most of of the money these days is server management and consolidation.
• It’s slow. Depends on what you do, but it can be pretty fast. That is to say, for normal things like running Word, Outlook, or a browser, it’s plenty fast.
• It consumes resources. True, but it’s not quite as bad as a fixed partitioning. A VM’s memory can be swapped ouf if it’s not in use, giving more back to the host. If you need all the memory back, you could temporarily pause the VM.
• It’ll let mactel users play windows XP games without rebooting. No, it won’t (unless you’re talking about solitaire). You need better hardware support (not just CPU, but GPU as well, and that’s nowhere close to happening yet)
• Nothing new, it’s the same as Virtual PC on Power PC. while similar, PPC Virtual PC is an emulator, which translates all x86 instructions of the guest to PPC instructions. No VMware product does that. Virtualization means only some of the instructions are translated… x86 instructions that don’t need to be translated aren’t, and thus run with a lot less overhead.
• VMware’s expensive. Not anymore. Player’s free, and Server is about to be free. Sure, if you want ESX, you pay a lot, but if you use it right, you’ll easily save more than you pay.

A lot of random articles talk about how you’ll be able to buy a pc and just switch between OS’s like you switch between applications today. Is this really what user’s want? I’m not sure that it is. If anything, it’s a lousy excuse for not being able to integrate software properly in a seamless user experience. Imagine having to switch between VMs just to go from your email program to your browser. That’s totally lame from any user experience point of view.
If anything, end users will use it to partition their computers (maybe an extended version of “fast user switching”) or they’ll use it to add complex services that run in the background (a virtual machine to do a simple home fileserver or webserver, for example). They’ll be what we’re calling virtual appliances, probably all with minimal or at least configurable footprint.
Power users are likely the only ones to use it extensively.. My guess actually is that many people who try to live on linux will start using windows again, because it will be so easy to run both. No need to fight the “make evolution talk to my exchange server” battle when you can just run Outlook in a VM.