these days my boss fav topic...consolidation. Our shop is 90% solaris ,dominantly SOL 10 running solaris zones, i have been playing with LDOM on T2000 and its very neat. Each logica machine can have its OK promt or GRUB, SAN LUNs can be mapped to different HBA WWN. Linux has good KVM and XEN i am not sure if the package is ready for prod environment ?