I have been working with Parallels 8 with a Windows XP machine on a 2009 MBA. This is just doable. As the MBA 2009 has only 2GB RAM and a Core2Duo 2.13GHz (but luckily separate NVidia graphics) it will work. You can't do anything else concurrently on the Mac, but it works. The WinXP VM has 1GB RAM and 1CPU (core). I use it only to run a single specific application. I have to upgrade to Win8 though. I need Win Office for some work with that specific application. That means I need to upgrade my Windows. I created a Win8 VM on my (faster) Mac desktop and copied it over to my MBA 2009. While this works it is very, very slow up until the point that it is unworkable. I am planning to buy a Macbook Pro 13.3in Retina when they are upgraded (and graphics performance is OK) so for now buying another laptop is not an option. I need to be able to work for a few months until I can upgrade my hardware. So my question is: what can I do on the Win8 guest OS so it uses the least CPU and memory? What can I strip, turn off, etc?
