Sure VMware has been around forever, so its stable, safe and well-integrated. However Xen blows it (and any other similar product) out of the water perfromance-wise. You need to consider if youre someone who needs a comfortable gui or someone who can get their 'hands dirty' with configuring a Xen-based system. I think if you're the latter, you wouldn't consider VMware unless you had a non-tehcnical or enterprise-level reason.
The eweek article you cited seems to be old and focused on Xen's enterprise product v3.0. It says it can't run windows. The current standard Xen download is currently at 3.0.2 and can run windows. The 'low hurdle' statement was in comparison to other enterprise-level products like vmware that costs about $500 per install because it comes with all the coprorate support etc. Basically VMware is a slow safe corporate product but for out-and-out techies its a pig in lipstick compared to Xen.
The audience of this board are mostly home enthusiasts and aren't probably gonna be paying $500 for any VM software for home use. The reality is that Xen works, is available for free download, and gives you about 5 times the performance of VMware if you have a VT-enabled CPU.
XenEnterprise 3 was just released and the eWeek review was from last week. I think the performance difference has to do with the virtualization strategy. Zen uses paravirtualization which involves changes to host OS (unlike VMware): better performance but a pain in the butt to install. And there is only one Linux distro that supports Xen at the moment (SLES 10 -- costs money).
I'm not sure better performance traded off against ease of installation etc. is a selling point to enterprises, who are the primary consumers of virtualization technology at the moment. They want to be able to set up, consolidate and manage servers quickly and easily. Virtualization makes sense because existing servers are only using a small fraction of CPU's potential performance.
Once a standard paravirtualization solution is baked into the Linux kernel the performance and easy of installation differences between the two will presumably become moot on Linux. See http

Also XenEnterprise is the commercial version of the Xen community release and costs serious money. The community release may be a bit ahead in support for Windows. Also note that VMware Server is now free.
Anyway looks like all this stuff is changing very rapidly and we'll all have cheap or free, easy to use, high performance desktop virtualization solutions on Linux in the near future --probably not great news for Microsoft.