We are looking to use vSphere to consolidate our Wintel boxes.
My strategy would be to virtualise everyting possible. The only thing that I believe we shouldnt virtualise is the vCentre Server as this manages the ESX farm (I maybe wrong there). So i can see the merits in leaving it physical.
But there are people of the opinion that we shouldnt virtualise our systems and service management tools as a failure in the fram would render them inaccessible. But isnt this a case fo just having mutliple farms and vmotion. I'm not an ESX expert but the argument they pose I believe is weak, esepcially when you conside the risk of the farm going down anyway.
At the ned of the day I want to have 90% virtual consolidation rather than 50-50 virtual to physical. I start losing the economies with so many physical boxes.