Probably not until May or so...I think they are waiting to see what impact the new parade and nightly show at the Studios will have on crowds before committing. However...the hours have been known to change based on the crowd level.
You can scroll back to Aug of 2011. Generally, park hours remain consistent with years prior. Hours will be released soon (by March, most likely). If you plan around 9-8 (common for Aug) you won't be disappointed if the hours are longer.