I feel there's only so many ways that Zos can rebalance and Tweak the current select of skills. And down the road rather than getting a new universal skill tree, focusing on expanding the current class skill trees would be a great way to freshen up the game.
Granted the work needed would be immense and Zos would probably not actually do this, but if it was an option, what would you like?
Altoholic, Frost Warden Sympathizer and Main
Glacial Guardian - Main - Frost Warden Zealot
The Frost Man Cometh - PC Frost Backup
Expanding Class Skill Trees 18 votes
3rd Morph for Class Skills
New Ability for Each Class Tree
New Passives to Expand Class Identity
1 vote
2nd Ultimate for each Class Tree