Yes. There is nothing inherent to a virtual guest that would limit the installation of a specific product or role. Only the supportability and performance of the products could/would potentially be different than when installed on a dedicated physical host.
I've virtualized CWA in multiple proof of concept and test deployments, but it's supported by Microsoft for production use.Jeff Schertz, PointBridge | MVP | MCITP: Enterprise Messaging | MCTS: OCS