In Savage Worlds's defense, you aren't supposed to just take the powers as-written. You're supposed to dress them up with trappings- giving them your own twist and all that. It's one of the advantages of the system to me.
I would love a unified Powers System, myself. It encourages creativity and playing outside of your comfort zone, in my experience. That said, I find Supers work best when they have their own power list. If only due to Superpowers tending to be different than fantasy magic and the like.
Though my reading has been limited, I think the BGB is the best book to base BRP Essentials on, since it's the most generic/universal of the books I've read, while having the rules that I prefer. That said, my time running BRP and its family is very low- I've ran about seven sessions altogether. But, I've been running RPGs for a few years now, in a variety of systems. I find BRP and Savage Worlds to be my favorite systems, though GURPS Lite and Unisystem are also very nice. GURPS Lite and the SW Test Drive Rules are a good basis for "Quick-Start Rules" as is, obviously (haha), the Quick-Start BRP Ruleset.
I feel like Essentials will probably be simplest form of chargen (no Fatigue or Sanity, likely, as well as little to no optional rules like Total Hit Points), a more concise skill list, the simplest combat options, unified powers (if only to save space- it's 32 pages after all), some tips and tricks for running different genres, and a small bestiary. I personally wish they made it an even 40 pages, but that might just be me. I'm sure that whatever comes will be done well and will hopefully entice more people to get into the BRP family.