Ulli Hankeln, owner of Sanbarrow.com VMware hacking site, wrote a software able to convert any VMware virtual disk from IDE to SCSI, without using imaging/cloning solutions:
I have written a patch that converts a XP-ide-disk into a XP-buslogic disk. No imaging or cloneing necessary.
All you have to do is edit the vmdk-descriptor and run the patch from BartPE.
It fixes disk-geometrie and boot-device in registry.
He posted the news but just few answered. If you are interested tell him and we’ll see the tool published.