Haven't seen this one suggested yet. This is just another possible solution to fix the new shard bombs to make it serve a function other than just being an inferior bomb. Its not necessarily better than the others, but just an interesting solution that could work even given its current damage. It would also make them an effective party weapon, rather than something that randomly scatters enemies and hurts your party. so now on to it.
Keep the original first part of the bomb (set it down. it explodes and makes the ring of shards. even the delay before the shards explode is fine.)
When the shards explode, anything that registers a hit is pummeled into the middle of the ring, instead of flung randomly about. Thus, you know that anything that takes damage is then concentered tightly together. In this way, it is effective crowd control with decent damage.
So basically, its the cross functionality of damage bomb and a vortex bomb. It has higher damage than a vortex bomb (less damage than other damage bobs) but it clumps the monsters together for only a fraction of the time. Whereas a vortex bomb pulls them to the middle and then holds them fast for a few seconds, the Shard bombs would knock them to the center but they'd be instantly free to move.
This doesn't sound like a bad idea after watching Tsu's video. The knockback does seem to hurt it's potential, because it is so random. +1 from me