EDIG has about 6 years left on the patents if memories are real and not 1980 flashbacks.  They also can continue to file suits after the patent expires on companies that were using their IP during the covered period.

It is rare that a patent is extended, but trademarks are good as long they are renewed without objection.  If there is an objection to trademark use, the USPTO decides.  In trademarks, an entity files by category -- example, you can have a Gibson branded refigerator and a Gibson guitar not from the same company.

John