Taking World of Warcraft in example, where you have two factions that are vastly different, race wise, and the fact that the "heroes" on either side have no means to communicate with eachother, I'm wondering how TES:O will do this. Throughout my experiences in Cyrodiil and Skyrim, I have yet come across anyone who is unable to use the english tongue (I won't count the spooky voice in Labyrinthian, cause that eventually spoke english).
So lets make an example where I (a Redguard) runs into a Nord. As of that moment, I have no grudge with this fellow, even though he is clearly of a different alliance than my own. He doesn't lift his sword or try any aggressive actions, and thusly I have no reason to do the same.
Now, the moment of truth - can I talk to this Nord? I'd like to say we both speak the same language. I've spoken to several Nords, and they don't seem to have a lot of language-difficulties. Then again that was 1000 years in the future, so perhaps it will take another millenia before all the races of Tamriel learns to communicate in the same tongue? I don't know.
What do you fellers think? Should cross-faction chat be allowed, or prohibited?