Doesn't seem like.
It is always complaining about "Invalid Vmdk file, please select another one" when I want to convert ANY systemdisk from our ESX 3.0 server. I used the newest available Version of vmdk2vhd (1.0.13.0).
I also tested the tool on VMware Server and it converts the disks without any problem.
Can anyone PLEASE tell me why this is happening?