Reunion Tower observation area is expected to reopen sometime in 2012, but no expected date has been given.
In the meantime, you can either eat at the restaurant or go up to the bar to be able to get a vew of the city from the rotating section of the ball.
On a clear day (or night) you can get a great view of the Dallas area. Standing 50 stories above the Hyatt Regency hotel in down town Dallas the observation level provides a 360 view of the surrounding area.
To the north the Bank of America building, now the tallest in Dallas. the former Texas School book Depository and the "Grassy Knoll" at Dealey Plaza; to the West the Trinity river and the Dallas Cowboy's home Texas Stadium in Irvine; to the East the Dallas Convention Center, the world's largest column-free exhibit hall, and to the South, the landmark Gilley's.
observation deck tickets $2.00 Adults, $1.00 Children, but the brouchures in the hotel provide complimentary access to the deck