I'm halfway tempted to call my sysadmin out of bed to check one of our systems that I'm quite sure has VPro to see if it is vulnerable. Fortunately my main server is an AMD Bulldozer box.
Regardless, if it runs AMT you should check it, VPro or not is really besides the point, it's AMT that is the problem, not VPro as such, which is just another marketing term for the ME and application suite if I understand it correctly, and if that were exploitable instead of 'just' AMT it would be much bigger (and worse) news.
But saying that all VPro enabled Xeons or even every Xeon is affected is needlessly alarmist.
Here is a wikipedia article on AMT:
If you look at the list of version you can see they all target Desktop and Mobile, no Xeons besides the one I listed earlier. The document you linked also explicitly states 'PC's', not 'servers', though it is definitely possible that some hosting facilities use (cheaper) desktops as servers.
Forgot the link:
It would be really nice if Intel would categorically state which Xeon line products are and are not affected.
I thought AMT was a component of VPro. I assumed all VPro systems had it based on early marketing of the management capabilities of VPro. They were just bundling management and security features. Memory too broken to be sure but that feels like what I said to a lot of people over time.