ZOS has over, or DID have approx. 700k subs, and doing the math they were making a nice profit. so I think this is being done to cator to the console players, knowing that a lot of them will initially reject a sub, this will get them into the game, andf those who enjoy will pay more or eventually subscribe...just a theory

Sure they are making profit. But not the profit they want to see.

Then again, sub based mmo's are a dying breed.

It's something that is slowly being phased out and I wouldn't doubt if soon all mmos besides wow become F2P or B2). I fully expect Wildstar to go this way soon with how bad those folks have been getting it. Guild Wars 2 is buy too play and they are doing very well.

Look what happened to Warhammer online; a game that decided to stay sub only and because of it eventually started losing money and had it's plug pulled (all fo which could have been saved if they went Free or But to play)

Apparently the Elder Scrolls fans asked for it, although I do not recall seeing many requests for B2P/F2P transitions over the past few months.

This is probably the only explanation and it has nothing to do with money of course.