I don't think that means much. I remember someone saying in this forum that 3.0 beta came with an AT&T carrier file that enabled MMS, but it was modified to disable it for the 3.0 GM. I bet the same thing's going to happen to 3.1 GM unless AT&T is ready to give us MMS/Tethering by then.
So after this week will the poll change to "3.1 Beta Next Week?" This poll is like those cults that predict the apocalypse, then when it doesn't happen, they make some excuse as to why it will be a different date.