UO is not going to Free to Play anytime soon.
The reason games go from monthly account subscriptions to F2P is because revenue from subscriptions is low enough to where profits come close to operating expenses. For these games, it's more of last ditch effort to keep things going.
Games that start out F2P from the very beginning have an advantage. Generally, they're less complex, have lower operating costs, and don't have as much at stake.
Now in UO's case, lets say you pitch the idea of F2P to the head of EA/Mythic.
He's going to ask "is UO making a profit right now?"
You answer: "technically yes"
Then he's going to ask: "If we go to free to play, how many accounts will not have to pay anymore?"
You answer: "all of them"
Head of EA/Mythic: "These current players that will no longer be paying 10 dollars a month for subscriptions, what service are they going to pay us for to recoup the $120 they give us yearly? We can't take away services that they already have."
You answer: "booster packs, and lots of them. $20 a booster pack"
Head of EA/Mythic: "You are going to be able to make 6 booster packs a year and assume that every account is going to purchase one just to make our profits even, just as where we are now?"
You answer: "yep"
Head of EA/Mythic: "You can't even fix bugs, let alone stop cheaters, dupers, and exploiters. How do you have the personel, the time, and the resources to create these booster packs?"
You answer: "uhhh....."
Head of EA/Mythic: "How many new players are going to join UO after going F2P?"
You answer: "I'm sure a lot of people will join!"
Head of EA/Mythic: "Do you have any hard evidence to back up that statement? Any case studies? Anything at all?"
You answer: "Not really. But a couple people I talked to said that they'd come back if it was F2P."
Head of EA/Mythic: "So let me understand this. You want thousands of players to stop paying $10 a month for thousands of accounts. $120 a year per account. Expect your staff to make 6 booster packs a year, charge $20 each for them and convince every single account to buy it, even though we sell booster packs now to paying accounts. Then, you expect lots of new players to join a game with outdated graphics and a steep learning curve, even though you have no proof that anyone new would be willing to try UO?"
Point here being is that EA is making a profit right now. Plain and simple.
If they're not, then they will either go F2P or sell the rights.
Until then, I don't know why this F2P thing keeps coming up.