Although numerous sources have reported it, Paul Kuharsky turned out to have the most information regarding the latest roster moves:
#Colts waive RB Darren Evans and WR Marshall Williams and sign S Stevie Brown to the active roster.
Darren Evans was impressive during the preseason, and should be signed to the practice squad (where Williams was cut from). The Colts need the depth at running back, especially considering Addai and Donald Brown's injury history.
As for Stevie Brown, he should be a boost on special teams if nothing else. He showed promise with the Raiders in 2010, his rookie year, and could develop into a decent safety. For now however, Brown's biggest impact will likely be special teams, where the Colts' gunners have struggled over the past two weeks.
Brown grew up in Columbus, Indiana, where he was a four-year starter at Columbus East. He attended the University of Michigan for four years, becoming a captain during his senior year. He was drafted in the seventh round of the 2010 NFL Draft by the Oakland Raiders. After being signed to the practice squad, Brown was promoted to the active roster for Week Two. He played in every game after that, including one start. He was cut for final cutdowns this offseason, and picked up briefly by the Panthers, but was cut prior to Week One.