The Elder Scrolls Online has removed the six-month subscription option from the game. Oh, sure, it seems innocent enough; it's just a change in billing options. But it's also one of those changes that's happened in more than a few other games indicating that the game was removing the need for a subscription... or that the game was no longer going to be playable at all, in the case of Warhammer Online.
The official ZeniMax response on the French forums is simply that players indicated they preferred the shorter billing options, so the six-month option was removed. General sentiment in the thread is that this answer is not entirely credible. If it really is a harbinger of something more to come... well, we'll find out about it in about six months. Maybe five.
[Thanks to Siphaed for the tip!]