Can anyone shed some light on whether or not you'll be able to make characters that belong to different alliances?

I'll be extremely depressed if I have to choose just one, because I want to be able to explore every region. The screenshots released so far look amazing, and I think (more hope) that this game may kill WoW, if not kill, maim for sure.

Yes you can make characters on different alliances. So you have no worries.

they have been really tight lipped on all the info like how many characters and what not but you will be able to join the other factions with alts. 3 games in 1 baby

Yep, they said interviews that a single character can only be a member of one faction. You can still make multiple characters though and have them be in the other factions.

Do you know if you can venture to enemy faction's areas? I would love to be a dunmer assassin in the bosmer woods.

you cannot