From what I've heard, the mages of Dalaran have succeeded in rebuilding their magical city and moving it to Northrend, leaving behind a massive crater. Some mages remained here though, who should spare some time to look at the bracers. If there's anything I know about mages, they can't resist a magical puzzle.
Take the bag of water elemental bracers and see if they can shed any light on the Stone's curse. Look for the Archmage Ansirem Runeweaver. I've dealt with him before, and his knowledge is vast.
The Stone of the Tides? Most interesting. It might surprise you to know that I wrote a tome--several years ago--pertaining to the legends of the Gurubashi Empire. I do know quite a bit about the Stone.
At least one of these bracers appears to have some magical residue I can analyze.