Has this been discussed or considered yet? I know that most of you here would bash on me for talking about neverwinter or WoW (when it worked). But without Voip, i would have never met any of the truley awesome e-friends that i have. Rust is another good example, can you imagine any modern title of 2014 without some sort of vocal communication built in? (especially one which is sub based?).
There will be a lashing of pink sunglass bearing fans on how their guild uses the oh so great mumble, teamspeak, or sometimes even (*cringes*) skype. Thats not the point. Voice chat in-game also helps eliminate lost text-tones or any text lost for that matter due to combat. If you were typing in Rust, my base is under attack! People would lol and ask, "why are you typing then?" The only thing typing was ever used for was global communication for misc reasons, but then again, most people who were already friends used private friend messaging.
But how did they get to be private friends to begin with?
Ever play with someone in a game without voip, get close with them and then chat with them on skype to figure out they mouth breathe or are 6 years old? Sometimes its nice to figure this stuff out beforehand. Go ahead and discuss how people might "abuse the system" (a term overused as ANYTHING can be abused in ANY game according to the naysayers) but it can work, and there is no reason why it shouldn't be in ESO. It's an MMO and player to player reactions in-game should be highly substantial.