I highly doubt that this will be a free-to-play model with microtransactions used to support it. I can potentially see a free-to-play model that limited you to like level 10-20 until you subscribed, but thats really just a demo with your standard subscription model, which is honestly the best way to go about it (assuming the level limit allowed you to at least experience enough of the game to get you interested, as most MMO's are really quite boring until the higher levels).
I can't even fathom this being a true pay2win game, where you get unlimited access to everything for free but those who spend ridiculous amounts of money get such massive bonuses that someone who doesn't pay anything can't even begin to compete with them. I certainly wouldn't rule out a cash-shop that allows for cosmetic items though, which again I'm completely fine with as long as they don't affect game play or balance in any way.
So far this seems to be developing as a true AAA MMORPG, with much more emphasis on the RPG part of that than your typical MMO (due to its close relationship to the Elder Scroll series).
As far as PvE/Raiding, you may find that it is significantly different from your standard MMO. The holy trinity (healer/tank/dps) style of gameplay that you see in most MMO's has been very much downplayed by the dev's, and I think thats a good thing. Small group and even large group dungeons and what not will be available even at the highest level, but from what I can tell they are putting a lot of emphasis and thought on the PvP aspects of this game, specifically the 3-faction war that will be going on in Cyrodil. Thats not to say this a PvP centric game, with PvE being an afterthought, but I wouldn't expect it to be like WoW where PvE is the center of the entire game outside Arenas.