ESPN has the scoop. This is obviously very big news because Braun just won the NL MVP and, if Braun's appeal is denied, he would miss 50 games next season. Also, if this turns out to be true, the baseball punditocracy will never let you hear the end of it.
A few things to consider before you go getting all righteously indignant:
1. From the linked article: "The positive result was triggered by elevated levels of testosterone in Braun's system, the sources also told "Outside the Lines." A subsequent, more comprehensive test revealed the testosterone was synthetic -- not produced by Braun's body.
Every individual naturally produces testosterone and a substance called epitestosterone, typically at a ratio of 1-to-1. In Major League Baseball, if the ratio comes in at 4-to-1 or higher during testing, a player is deemed to have tested positive. The sources did not indicate how high above the threshold Braun's sample tested."
So, as of now this is NOT a positive for steroids.
2. Ryan Braun's career isolated slugging (ISO): .251
Ryan Braun's 2011 ISO: .265
So, whatever Braun took -- if he in fact took anything -- did not provide a magical boost to his power numbers.