Not sure if this is the same problem I have, but seemingly at random the mouse pointer disappears AND every mouse movement now moves the character (or the world) around, shifting the perspective. I can still move and activate powers using the keyboard, but it is rather disorienting. It seems to happen equally on both my characters and I have to log out for it to reset, nothing I do with mouse or keyboard seems to change it. To make things worse, I can't log out without first alt-tabbing to another program, centering the mouse over where the ESC menu will be, and alt-tabbing back. It is not an immediately critical flaw at this stage, but obviously it needs to be gone before launch.