JohnP,
Over the years Inter-Tel had created products that would allow you to do what he wants, but those were dropped or modified and incorporated into other systems; ie Intelligent Router. They still provide the developers package so if someone was inclined they could create something that does what they want it to, within the confines of the OAI stream; which is pretty powerful.
That being said I do believe that if they wanted to "fix" some of the issues that technicians have with the 5000 that they could, but I don't believe that they really want to put a lot of money into the development of this product or its future. Although they currently generate a good amount of revenue on this product it doesn't seem like it fits in the path that they want to take the company in; of course that is just my opinion.
Thanks,
TE