Doesn't look like it, at least in 10.1 M040, both the Reassign function and the calendar delegation function only drill through to specific users.
If this is key, your only main option which may not be ideal, create a dummy account as a "hub" role and share the login info with the team in question, and set the task/delegation to that account. Also put in a rule that anyone on the team who wants to do the assignment MUST reassign it to themselves first so you can track who did what, so no actual processing gets done on the dummy role.
Daryl
