Pulling bricks towards an explosion? That's a simple edit.
In the Projectile datablock,
brickExplosionRadius = 0;
brickExplosionImpact = true;
brickExplosionForce = 20; //This line, set it to a negative value of whatever magnitude
brickExplosionMaxVolume = 200;
brickExplosionMaxVolumeFloating = 200;
For special effects in general, it could easily be done. You can get emitters to spit out particles in reverse direction now (Thanks again for that fix Badspot) so you can effectively reverse every part of an explosion's emitters. Actually if you know how to work out a few of the emitter and particle datablock lines it would only be a 10 minute ordeal to take any explosion that does not have an explosion shape and reverse it.
Edit: Oh yeah, pulling players can also be done, but it's a 1 pull deal per explosion.