Thanks Robert. While the link you have directed me to states "CBWFQ is supported only with VMware ESX and ESXi 4.1 and later" under the "Additional Guidelines and Considerations" heading and also shows the following configuration example in the appendix
class-map type queuing match-all vm_gold_class
... the actual confiuration guide for version 4.2(1) SV1 (4) says somehting different under the "Guidelines and Limitations" heading - "Queueing is only supported on ESX/ESXi 4.1.0 hosts"
In addition to this, I can confirm that the keyword "queuing" from the class-map type is not available on my deployment which is on EXSi 5.0. I suspect that your link was written prior to testing of this on ESXi 5.0 and it was just assumed it would work on later versions.
I would like to be proved wrong on this. Perhaps there is something I am doing wrong which prevents the configuration of "class-map type queuing" ?? When I enter "class-map type ?" I only get the option for keyword "qos".