Per Richard Durrett, Roy Oswalt has cleared waivers, and per TR Sullivan, a trade is "possible."
The panicky -- and quite possibly ownership-driven -- $5 million signing of Oswalt has not worked out particularly well for the Rangers. Oswalt has a ridiculous 5.94 ERA, and while his underlying xFIP of 3.49 suggests he has actually performed much better, he has also seemingly been far too prone to throwing hittable pitches.
Regardless of the outcome here, his signing will remain a black mark on the season, though hopefully a negligible one. While he has done nothing to inspire his ability to remain a starter, he would be a nifty right handed reliever who could come in to mess with teams setting their lineups to face a Matt Harrison or Derek Holland in the playoffs. ZiPS gives him a serviceable 4.32 ERA as a starter for the rest of the season (4.10 if you adjust for Arlington), which could be missing how much he's aged, or it could be suggesting keeping him around is a good plan for Texas.
Unfortunately, Oswalt has made it clear he's not a team player, with huffy post game interviews over disliking his role, and refusing to pitch relief innings. If asking Oswalt to fill a role that helps the team turns him in to a cancer, Texas probably needs to consider getting what they can out of him, and second guess paying $5 million to an over-the-hill pitcher in the future.