SELECT *
INTO #TempNewQuery
FROM (
    << My New Query>>
) AS x;

SELECT *
INTO #TempOldQuery
FROM (
    << My Old Query>>
) AS y;

SELECT * FROM #TempOldQuery
EXCEPT
SELECT * FROM #TempNewQuery;

SELECT * FROM #TempNewQuery
EXCEPT
SELECT * FROM #TempOldQuery;

DROP TABLE #TempNewQuery;
DROP TABLE #TempOldQuery;

The first result set will be items in the old query but not in the new one.

The second will be the items from the new query but not in the old one.