Well, this is a mild surprise. It's retroactive to March 21, which means he can be activated as early as April 5 when the Phils visit the Cincinnati Reds.
I guess one consequence of this is that it gives the team more time to resolve its roster issues--which might mean a new lease on life for Travis Blackley and/or J.D. Durbin. Also, Clay Condrey presumably can now pack his bags for Philadelphia.