Obviously it's early days, but I'd really like to see you tackle the Sword Coast Adventuring Guide subclasses, a few of them are very specific to Faerun lore and also provide some interesting alternative playstyles.
For example, the Bladesinger Wizard subclass sets up a player for something a little closer to the old Fighter/Mage of BG1&2, being as capable of hitting things as a warrior (assuming stats assigned appropriately, or rolled stats which I do kinda hope to see here).
Arcana domain cleric would be an excellent fit for a cleric devoted to Mystra in forgotten realms too, and once again, allows a player to mix up the standard dynamic of a class (cleric this time).
Plus, who doesn't love battle ragers!