There is room for more Talents/Specs for adding to grenades I am thinking.

I believe the Demolitionist (sp?) has some good stuff for grenades, but I'd like to see a Grenadier in the Soldier book.

The Engineer:Saboteur is what you're looking for. I'm hoping they don't do too much crossover stuff.

I'm aware of Saboteur and Demolitionist, they're a bit more general. I am thinking talents to expand blast radius, talents to lower Advantage costs, additional effects to jury rigged onto them like tamping them to provide Pierce or Breach, as well as, some of the existing stuff like Powerful Blast and Strongarm.