A execução de HVRemote ajudou a elucidar a causa, e acontece que firewall no cliente foi configurado incorretamente.
O Dragon é protegido pelo Norton Internet Security. Embora eu tivesse uma regra de firewall concedendo explicitamente acesso ao servidor, ela era colocada na parte inferior da lista de regras, portanto, não tinha o efeito pretendido e a comunicação do DCOM era bloqueada pelo firewall de qualquer maneira. Depois de mover a regra para o topo da lista, consigo acessar o servidor através do Gerenciador do Hyper-V sem problemas.
Para esclarecer o problema, veja a documentação on-line para O Norton Internet Security diz:
The Smart Firewall processes Traffic rules before it processes Program rules. For example, when there is a Program rule that allows Internet Explorer to access Internet using port 80 with TCP protocol and a Traffic rule that blocks TCP communication through port 80 for all applications. The Internet Explorer application cannot access the Internet as Norton Internet Security gives precedence to Traffic rules over the Program rules.
Within the list of Traffic rules, rules are processed in order of appearance, from top to bottom. Program Rules entries are not processed in order. The rules within each Program Rules entry, however, are processed in order of appearance, from top to bottom.
For example, you have a Program rule for the Symantec pcAnywhere application that blocks the use of the application with any other computer. You add another rule for the same application that allows its use with a specific computer. You then move the new rule before the original rule in the program rule list. Norton Internet Security processes the new rule first and lets you use Symantec pcAnywhere with that specific computer. It then processes the original rule and prevents its use with any other computer.
Como final feliz, aqui está o instalador do openSUSE em execução em uma VM hospedada no Wyvern e exibida no Dragon :
