Hmmmm...good question.
If you had Cisco switches and were deploying DTP and ISL trunks, and other Cisco protocolos, and were migrating to 3com, I would say yes.
But the other way around....unless there are specific 3Com protocols that are used on the switches, or perhaps even a different way of implementing open protocols with proprietary extensions, then you should be OK.
It would really take some analysis of the configurations and a full understanding of the environment.
HTH
Victor