I would really like to see more customization options in the game, but I would seriously hate to see this game become a SW themed WoW...
Perhaps the best option would be making interface elements behave like lego bricks, so you could move the main elements (minimap, chat, quest pane) to several preset locations.
That could preserve interface consistency and allow for multi screen players to organize a neat centered HUD.
But DPS meters, BossMods, SpellAlerts destroy the authenticity of the game feel.
If you need to find the best rotation - Believe me, best theorycraft is done on paper... or just find some ElitistJerks who will tablespoon feed you with the perfect rotation.
If you need BossMods - Learn to read visual cues from the bosses. It will make your eye sharper and reflexes better in the long run.
If you need Spell alerts/Buff reminders - You should learn to count to 8 or whatever you cc lasts for. With practice, you will just feel how long it lasts.
In a world with AddOns that play for you, the winner is the one who has the right addons and sets them better.
I'd like to see SWTOR a world of game skill and not macro jugglers and addon masters.