After a long search on CD Now…I thought it may have been John Williams - it seemed like he’s composed everything in the last two decades. However - it’s not him - his “Olympic Fanfare and Theme” isn’t the song I’m thinking of…it’s the one that they play as NBC begins and ends it’s broadcast each time it airs the Olympics (lots of trumpets - and now a spot gag done by NBC with the cast of “Will and Grace”) 
Isn’t it Copeland’s “Fanfare for the Common Man?”
Nope it’s not “Fanfare for the Common Man.” It’s not even by Copeland.
It’s called “Bugler’s Dream” by Leo Arnaud.
John Williams wrote a fanfare for the 1984 Olympics and NBC had to use some other music by Williams and others until they could buy the rights to Arnaud’s work from ABC.
Pretty sure it is Copeland’s composition. I also recall ( i think) the most often used version is by those old 70’s rock dinosaurs Emerson, Lake and Palmer.
You can get a recording of Arnaud’s “Charge: Bugler’s Dream - The Olympic Theme” on the CD “Arnaud: Symphonie Francaise, etc.” available through Amazon.
Masatoshi Mitsumoto conducts the Polish Radio Symphony Orchestra.
There is also a rather goofy MIDI of Arnaud’s piece at http://www.armory.com/~keeper/midiall.html
(go to Bugler’s Dream). I love this music (not the MIDI) - it makes me want to reach for the remote faster, aim higher, and press the buttons stronger to watch the Olympics.