Last Friday, the Lions released three players: Kirk Barton, Paul Pratt and Copeland Bryan. Only the move involving Pratt got any publicity because it was in conjunction with the Dre' Bly signing, which is why I didn't know about the news involving the other two until I went to the Lions' transactions page on their website.
The Bryan move is a little confusing to me, because Tim Twentyman is reporting (via John Niyo) that Bryan has been placed on the injured reserve by the Lions with a knee injury. I don't know if this is one of those situations where Bryan had to clear waivers or something before being placed on IR, but that would make the most sense since the Lions are saying he was released. I suppose we will probably hear something definitive in the next day or so.
As for Bryan's injury, it means there will be one less player to compete for a spot on the roster at defensive end during training camp. Losing Bryan isn't a crushing blow or anything, but it does negatively affect the depth at DE.