It would be advantageous to be able to assign all test suites in a test plan to a user. Currently one must assign each test suite individually. The workflow in my current project is to use an unassigned test plan as a template, use the rerun feature to create a new test plan then assign all tests to the lead tester. They may delegate individual suites or tests as they see fit.
This feature might be provided by an "Assign to" button / link near the top of the "Edit Test Plan" page. Clicking this might popup a dialog offering selection of user with an apply and cancel button. Clicking apply would assign all test suites to the user.
An enhancement would be to allow selection of individual test suites / configurations to which the change would apply, e.g. via select tick boxes next to each test suite / plan (or a more modern UI multiselect implementation).