Since Microsoft released the Windows Phone 8 SDK, I've had some problems. First, the emulator requires Hyper-V and SLAT support, which is not available on my trusty old Latitude D830. And I'm sure there are lots of people that don't have the newest generation CPUs in their machines. That means they can't test their apps on the emulator. Naturally on device works, but that's not always the best way.
Another problem was pointed out by a friend: there are lots of developers that have done apps for iOS and might want to port those to WP8. They can't just start Windows on Parallels and use the emulator there. VMware supports SLAT virtualization (at least on Windows, not sure about OS X), so it should be possible to run Windows 8 under VMware and the emulator would work.
Personally I run VMware virtual machines on my desktop and if I install the Hyper-V role, I can't run VMware. This is a problem. So I either have to reboot every time I want to run the emulator or install another Windows 8 in a virtual machine and run the emulator there. Both are cumbersome.
I kinda understand why Microsoft made it this way. They have a strong virtualization platform and as we've seen with iOS and Symbian emulators, it's not the same running the app compiled to x86 and on top of another OS. There are problems that are not on the device or that don't appear on the emulator. It's much better to run the actual ROM image that is on the device. But to require SLAT and disallow other virtualization at the same time is not nice.
Hoping MS could fix this problem, but I think it might not happen. I've been thinking about getting a new laptop for some time and this is one more reason for it. But since my old machine works so well and the only thing I'm needing is basically more memory, I haven't done it yet. Maybe it's time.
It'd help if Nokia would send a Lumia 920 and Microsoft would send a Surface... ;)