VMWare is working on a new feature so you’ll know more about the status of your VM’s. The VProbes feature attempts to do that and is available in Workstation 6.5.
If you are wondering how to attach a Windows share of .iso files to XenCenter, here is a video on how to do it.
I created this video that shows how easy it is to add NFS shared storage to Citrix XenCenter.
This webcast from Microsoft is long and Mark Russinovich (Microsoft, SysInternals) discusses several topics, but about 17 minutes in, Mark whiteboards Hyper-V and how it works. After that, he whiteboards some on Softgrid.