I for one hate fully voiced characters unless it is based in a game with such linearity as Mass Effect, Mass Effect was quite linear as the Quests are all pre-set and doesn't change throughout the main quest arc, whereas Skyrim is a much bigger, non-linear game where you have a lot more side-quests plus the radiant story added in to Skyrim, you just can't add a voice to TES characters unfortunately, but in a way you do add a voice in a sense as you imagine the voice of the person and how they would be expressing in game, as it is your character not "Hawke" or "Shepard" it who you want, and in a sense the person you create would have the personality of you, therefore you are in a sense the voice, and you are the person that decides on what to say and how you feel they would express them, it is the whole point of Role-playing, to feel that you are the character, not a mere-bystander retelling events...
Gods, how I hate it when people invoke the 'this is RPG' line. When I play the
real tabletop roleplaying games, with dice, storyteller and a pile of sourcebooks, then it's
all about imagination. I draw my characters' portraits, I make up their voices and write pages of backstory and personality that actually have an effect on the world. In cRPGs like the TES series, you don't have this essential feature of an intelligent being overseeing the world and plot at all times. Sure, you can
imagine things, but they mean absolutely nothing in a computer game restricted by however much the developers have manged to implement. Your character is limited by the technical and fabular restrictions of the game - which in TES is: nameless, backgroundless, personality-less voiceless and often even genderless.
Of course, computer 'roleplaying' is never going to be like its pen-and-paper inspiration in terms of freedom, possibilities and complexity, so it has to find other ways of making itself remotely as enjoyabloe.
Your character doesn't have a backstory, because that would require either restricting you to one or a few predetermined backgrounds (which many people may not be happy with) or an infinity of them (like in tabletop storytelling), so the easiest way out of this problem is leaving the whole thing up to the player's invention and interpretation; it makes the character slightly disassociated from the gameworld (their background won't reflect on it as it would on a pen-and-paper game), but at least allows the game to be finished faster than the centuries it would need otherwise.
Likewise with personality and gender, although here skillfully applied limitation to a few general archetypes could probably be forgiven - almost all of it is dialogue stuff anyway, so not nearly as effort-demanding as a complex backstory. It's much more possible for the character's behaviour to have effect on the world, and it has been done already (Bioware's games are not yet perfect in this regard, but going in the right direction). Removing the player character's unisixness is even easier, though so many games unfortunately don't bother with it.
With voice, it's pretty much the same as with personality. You already get to customise your character's appearance (their 'portrait'), so why not voice them and customise their speech in a similar fashion? And before you start whining about how much work it would take, how many things would have to be recorded and so on, allow me to assure you that it has been done already - a few years ago in a game called
The Sims 3, where you had a choice of three voice bases for either gender (for advlt sims, at least) and a slider allowing you to adjust the pitch however you liked, resulting in a sufficient number of combinations to satisfy even someone of my finickyness. And pitch-control is hardly the summit of technological advancement - just as well there could be various special filtres, echos, volumes and other such, all dynamically applied and requiring nothing but a recorded voice base for either gender.
Of course, by this point the discussion has no significance for Skyrim, since implementing something like a fully-voiced PC would have to have been planned and worked on from the very beginning. Still, it's worth noting that voice customisation is
not nearly as impossible as way too many people seem to think.