MMO's are exactly the same, but instead you pay a monthly fee.
This is what happens when a company lusts for money and forgets what made it famous in the first place.
Apparently, there is some rumor floating around that it will be F2P.
I'm fairly horrified at a TES Online game, and I'd be even more horrified (if it were ever possible) to see it go F2P. At least with subscription, everyone is an equal customer with equal potential to play, while with a F2P, the only people who ever get to have all the content are the people doling out anywhere from 50 to 250 dollars a month to play. Unfortunately, it is VERY likely that TES:O WILL eventually go F2P if it doesn't start as such, as its a cash cow and a more viable market strategy (despite certainly NOT being consumer-friendly).
They can say they're gonna be as lore-friendly as possible all they want. But all MMOs, by their very nature, suffer from something called content inflation. Eventually, they are going to hit a brick wall and will be forced to seek permission to pull stuff out of their behinds or allow the MMO to ultimately stagnate. Another game that comes to mind that originally attempted to be as "lore appropriate" as possible was Lord of the Rings Online -- I think that game may very well tell us a lot about how TES:O is going to be.
As for Zenimax not going with a new IP.... well. I agree that a new IP likely would have been too risky. That said, I think Bethesda should keep its nose out of the MMO business, lest it gets another taste of an anti-consumer river of cash like it did with DLC (hahaha.. I'm sure you older TES players will remember the difference between those Morrowind official mods and those uh... "well crafted" Oblivion pay-for official mods). Besides, nothing about Bethesda screams "we know what we're doing!" when it comes to MMOs.