Update 3/21/13: The crazy missile damage hotfix today appears to be addressing some of these issues, but has said to be temporary. Sounds like they’re not sure if they’re going to remove splash damage or not. Read about the missile damage hotfix news here.
Original Post: The latest development from PGI regarding the broken splash damage is that it’s being removed form the game as of April 2nd until further notice. What does that mean? Weapons currently doing splash damage will only damage the points they contact. This will cause much less damage from missile volleys as well as probably less PPC and ERPPC damage.
In case you missed it, Amaris the Usurper did an extensive amount of testing into missiles and their damage being mysteriously multiplied on some mechs which lead the developers into an investigation into splash damage. They realized that a lot of the new models (particularly ones with small hitboxes) were receiving in the ballpark of 12 damage per missile (instead of 2.5) because of borked splash damage physics.
Hopefully everything will be fixed and ready by the April 16th patch, updates will be posted as we get them.