According to cisco documentation current products do this just fine. I believe the use of the word "guest" here does not only refer to the "guest vlan w/lobby ambassador" concept.
â¢ Manage Bandwidth by Guest User Type. In addition to tailoring user portals, Version 4.2 enables administrators to customize bandwidth privileges for specific user groups. Administrators may easily restrict bandwidth to low-priority groups such as short-term consultants, for instance, while assigning higher throughput to groups requiring fast connectivity to resources such as enterprise resource planning (ERP) systems or research portals. When a guest logs into the network, the WLAN controller automatically enforces the bandwidth policies assigned to the particular guest's user group. The policies are applied on downstream traffic, helping to ensure that administrators are able to control network resources efficiently.