Now if it were truly plausible at this time to have really realistic and customizable speech synthesis in a game or editor for a game, then this would truly be my first choice and I think since we are talking about all future versions of TES I think it's safe to say that this definitely should happen when it becomes possible.
And for anyone who says that reading the text on a console is a tedious and annoying... Play Fable 3. (Not to down grade it at all, it is a great game and you should play it, but if you do you might realize what I'm talking about) There are also many ways in which you can make a text based dialog work quickly and effectively. (I wont list at the moment, but it shouldn't be too hard to figure out yourself)
Anyway, on to what you think, (I've enabled multiple choice in-case you think they should change it up between games)