According to sources, head writer David Kreizman, who is credited with being responsible for the big picture direction of WWE heading into this year's SummerSlam, is not responsible for the main creative ideas. The main direction this year was developed by Vince McMahon, with Triple H leading the proposed McMahon-family heel turn storyline.
Kreizman isn't mapping out the ideas, rather he is simply interfacing with other division heads that need to be kept up to speed. WWE officials Ed Koskey and Dave Kapoor have been rounding up ideas from the writers.
As far as top storylines heading into this summer, everything that was planned out a month ago is going exactly as planned leading into WrestleMania XXX. Whatever late-changes are being made each week to TV scripts are not effecting the big picture plans that will come to a head at WMXXX.
The planned main storyline for WrestleMania XXX, which will be featured more prominently as SummerSlam approaches is the current McMahon family angle. According to reports, the angle is in its' infant stages and will explode following the conclusion of SummerSlam, as the focus at that point will be building towards WrestleMania XXX in New Orleans next year.