Catch over fence
 

I didnt see it but apparently Sports Center played a clip where a player jumped in the outfield and caught the ball and ended up over the fence without coming down in the field. Is that still an out?

Caught while falling over fence
 

Yes, it is still an out as long as he holds onto the ball.
He cannot jump over the fence and make a catch for an out.

http://mlb.mlb.com/video/play.jsp?co...82246&c_id=mlb

Regretfully, the clip doesn't show the ball lying on the ground after the fielder went over the wall.

There was a play from a college game where a player jumped over the outfield fence and made a catch. As long as the player makes the catch before landing out of play, it's a catch even though the ball went over the wall in flight.

Here's one such play:
<iframe width="420" height="315" src="http://www.youtube.com/embed/-7_1sLagZ0Q" frameborder="0" allowfullscreen></iframe>

He made the catch while part of his body was still in live ball area so it counts.
That's right, Walt. The ball came out of his glove and rolled under his back but the umpire never saw it. In fact, the only one who saw it was a fellow in a yellow shirt who had the perfect angle on the play.

Here is the video for those who didn't see it. It's pretty much what you saw before but the slo-mo starting at the 1:00 mark shows the ball rolling under the fielder Baseball Video Highlights & Clips | Must C Curious: Maier appears to make a stellar grab - Video | MLB.com: Multimedia

I'm guessing this is the catch the OP had in mind:

Greatest catch ever to end a baseball game. Ever. Seriously.

That's the one I had in mind.

He would be out if he held on the ball. OBR 6.05(a) Comment. KC got away with one. Positioning is everything.

"...He made the catch while part of his body was still in live ball area so it counts..."

I think the OBR rule is that the leap into the air by the fielder must originate with both feet in live ball territory, so technically a fielder (if he is very close to the DBT line) could make the catch with his entire body over DBT and still get an out on the catch.

If he hasn't hit the grouind yet - yes.