MLB and the unions have agreed to several changes. I haven't had a chance to read over actual current agreement, but a summary is provided at the link above.
The biggest changes IMHO:
Increasing the number of random tests during the season and offseason.
Permitting public announcement of the specific substance that resulted in a player's positive test result or discipline.
The parties have added over 45 performance-enhancing substances and stimulants to the list of prohibited substances in the program since the publication of the May 2008 Program. "
They're also testing for HGH, but only in the offseason. Also they are changing/clarifying the rules for the collectors and the appeals process.