Looks like VMWare is struggling a bit lately with PR as they have compared their light weight virtualisation product to Hyper-V based on some dubious metrics. VMWare would like you to think that Hyper-V is slower and less stable because it consumes a larger disk foot print but Microsoft.
Microsoft has hit back however:
“ESXi as a 32 MB hypervisor” and “the Hyper-V hypervisor and virtualization stack combined is about 20 MB, ~19.4 MB for the virtualization stack and ~600k for the hypervisor.”
I think it is great that Microsoft are pointing out all the FUD that VMWare has been touting about Hyper-V lately (see http://blogs.technet.com/virtualization/archive/2009/06/12/vmware-fud-fiasco-final.aspx ) as clearly they are running scared with the up coming launch of Hyper-V R2 and just want to get as many jabs in as quickly as possible before they get KO. Having already lost 28% of market share with Hyper-V (R1) it is not going to take long for Microsoft to take the lions share of the market due the massive cost savings their product has to offer.