We will be doing this within the quarter (we are still on SharePoint 2007, but will be upgrading soon), so I don't have an answer for you now, but I will in a bit.
Note that in the document it states: "The major degradation stems from the lower IO performance when running in a virtual machine..."
This seems to be a bit alarming, as in, if properly architected, why would they expect lower IO performance from the VM? I'm not a Hyper-V guy, nor am I completely familiar with how they set up this test (didn't get that far), but I'm a bit suspicious. Okay, I'm very suspicious.
Perhaps a question for you. Take a look at a VM of yours with the most intensive I/O (perhaps a SQL server, etc.), and are you ever stressing any of your disk I/O? I have have a love/hate relationship with most system requirements documentation. Here is why: http://itforme.wordpress.com/2010/01/03/resource-allocation-for-virtual-machines/
