Let's do an exercise. Assume that the same six classes as the Trilogy are in play (nothing new), but that each class has two different jobs that you can choose from to start out the game as. What jobs would you want associated with each class?
That would be awesome. I'd imagine an Engineer having unique abilities that aid one in exploration. In the concept art we see a guy using a beautiful 3D map to guide himself around the planet, and maybe an Engineer has special class bonuses that increases the range of detection that gadget has for, if they're a real thing, Remnant technology. This would allow one to easily find loot for upgrades which means an Engineer gets better loot, to make up for less combat prowess.
Imagine if instead of choosing though, each class had two seperate leveling trees. One for offensive abilities, one for exploration abilities. Vanguard could combine his jetpack with an advanced biotic charge to more easily reach locations higher up or in the distance. Adepts would be able to destroy rock formations to reach better loot or make easier paths to locations. Sentinels get a mix of loot seeking technology while still being able to destroy certain kinds of rock formations. Infiltrators could get a special cloak that decloaks itself whenever you do something other than walking or interacting, separate from combat cloak so you can explore caves or outposts very steathily without attracting attention.
I dunno what could be done for soldiers, maybe they are strictly for combat, or get Mako bonuses. I know Inquisition tried something similar giving each class unique abilities, but it wasn't utilized to their full potential. There's a lot of potential with the next Mass Effect game, but I fear our imaginations go beyond the scope Bioware has in mind. Making two separate power trees could just be a waste a resources that could go into something else. Still, picturing a Vanguard using a jetpack combined with biotic charge to get freakishly high distance or height is awesome to me.
That or just give each class an exploration ability branch, rather than making two unique trees. A special class power for offense and exploration sounds cool though.