So what is the Elder Scrolls Online (PTS) really for (at the moment)? When I try to log in it says my information is Incorrect, even tho it worked when I was in the beta.

I can tell you what it is not for: discussing on these forums currently.

There isn't a PTR, it's in closed beta at the moment, and the most recent stress test ended a few weeks ago, there may be another stress test sometime before launch, if not then there will be an open beta.

This is not the forum to discuss it, and likely whatever is happening you don't need to concern yourself with anyway.

There is no beta this weekend. You should get an email with more information if you are invited to another test.