Mike Trout is the Los Angeles Angels prize prospect, and is currently playing for the Salt Lake Bees in the Pacific Coast League. He was taken with the 25th pick in the 2009 draft, and so far has proven to be a major steal. If the Angels didn't have a logjam in the outfield, he would probably be starting.
At only 20 years old Mike Trout is already a starter in AAA, and is not far away from the big league club. I'm sure the Angels didn't expect to move Trout along this fast, but based on his results he's forced their hand. Through 90 PA so far this season Trout has shown an exceptional eye at the plate, walking in over 12% of his plate appeances, while striking out in only 16%. He's also showing his tremendous speed, already swipping 6 bags. He has also showed above average power.
In AAA Trout plays center field, and with Peter Bourjos struggling he could take over whenever he gets the call. Physically Mike Trout is 6'1" and is known for his superb speed, stealing 56 bases in 2010, and 36 bases in 2011. He'll likely never produce a lot of home runs, but with his speed he should be able to rack up a ton of doubles and triples. Defensively he should be average to above average.
The main thing that's holding Trout back though is Torii Hunter, and Vernon Wells. Both have huge contracts, so they have to be played. Hunter is in the final year of his 5 year, $90 million dollar deal and Wells is in the 5th year of a 7 year, $126 million dollar deal. Wells is owed $21 million this year, and each year until 2014. The Angels don't have a spot for Trout yet, but if he keeps up his offense in AAA the Angels may have no choice but to call him up.