I'd agree probably thinking of Concourse Steakhouse, but it would have been longer than 10 years ago. It was on the 4th floor of Contemporary - where the Contempo Cafe is now right under the center mural. We ate there for 14 years on our family summer trips to Fort Wilderness Cabins - we could hop the boat to Contemporary, eat a great steak at Concourse Steakhouse (sauteed onions on the side, and creamed spinach). We were very disappointed when it went away in 2008, but very excited when Wave became Steakhouse 71, as it brings back a good, moderate priced steakhouse to Contemporary which had been a tradition for us for so long.
Going back 10 years, there were no other steakhouse spots at Poly or Contemporary. 10 years ago, the only "steakhouses" would have been Yachtsman at Yacht Club, Shula's at S&D, Le Cellier in Epcot Canada, Artist's Point in Wilderness Lodge, and Turf Club in Saratoga Springs. Some other restaurants serve steaks, but probably wouldn't be confused with a steakhouse...and some of the other steak spots wouldn't have been open 10 years ago.