The answer is : "Both"
State Rewind is live for laser weapons, so it is much easier to hit fast movers or lagshielded mechs, which allows them to be damaged the way they are supposed to be.
And SRMs/SSRMs/LRMs are having issues with splash damage causing the damage of these weapons to be increased or decreased in unintended ways. The small mechs (the Commando is the poster child for this) take MUCH more damage from an SRM6 than they should in certain situations, other mechs take more or less than they should due to the way the splash damage from millses interact with the hit boxes of the mechs.
Splash damage is going to be removed untill they get it working right. Many people, including myself, think that they should just take out splash damage and keep it out, but it is possible that some form of (correctly working) splash damage is beneficial to the game, we will just have to wait and see on that.
Edit: tweaked the wording a bit to better express my point.
Edited by Tickdoff Tank, 16 March 2013 - 01:27 PM.