Todd already confirmed auriel's bow is gonna be important in the dawnguard plot.
I want to see Umbra and goldbrand.
Clavicus Vile reclaimed Umbra, and Goldbrand was supposedly wielded by Emperor Titus Mede II during the Battle of Red Ring (Probably the only reason that weak fop survived, he was twinked with a badass, OP Artifact). Doubt it's still stored in the Imperial Vaults though, since Boethiah wouldn't let her instrument of slaughter lay dormant for long.