Elder Scrolls Online may not be hosting an open beta
"We will not be holding a traditional open beta, but if you sign up to participate in the ESO beta prior to launch and are eligible per our Terms of Service, you will get an invite to a future beta event. We will be holding several very large beta sessions that include beta key giveaway promotions before the game launches."
This has upset many mmo fans, who bided their time on the initial closed beta application phase, with the hope of getting in on a bigger, more complete, and less involving open beta phase.
Typically, most mmo games in development move from a pre-alpha test phase, to either a closed or open alpha test, and then onto a closed or open beta test (sometimes with location tests dotted about in between) followed by a soft or hard launch of the finished game. The Elder Scrolls Online public tests have skated quickly between location tests, to closed beta test, and presumably straight onto a hard launch, which is ultimately good news for gamers, who will get their hands on the game much quicker, but may leave a few extra bugs hiding deep within the games code, to be found at a later date.
They are yet to elaborate on what they could mean by "traditional open beta", however, and it could just mean that they're opting for a different approach to their launch. We'll just have to wait and see.